diff --git a/packages/happy-dom/src/browser/utilities/BrowserFrameNavigator.ts b/packages/happy-dom/src/browser/utilities/BrowserFrameNavigator.ts
index 5f6b010a..cc5b1a33 100644
--- a/packages/happy-dom/src/browser/utilities/BrowserFrameNavigator.ts
+++ b/packages/happy-dom/src/browser/utilities/BrowserFrameNavigator.ts
@@ -93,6 +93,8 @@ export default class BrowserFrameNavigator {
 		const width = frame.window.innerWidth;
 		const height = frame.window.innerHeight;
 		const devicePixelRatio = frame.window.devicePixelRatio;
+		const parentWindow = frame.window.parent !== frame.window ? frame.window.parent : null;
+		const topWindow = frame.window.top !== frame.window ? frame.window.top : null;
 
 		for (const childFrame of frame.childFrames) {
 			BrowserFrameFactory.destroyFrame(childFrame);
@@ -104,6 +106,8 @@ export default class BrowserFrameNavigator {
 		frame[PropertySymbol.asyncTaskManager] = new AsyncTaskManager();
 
 		(<BrowserWindow>frame.window) = new windowClass(frame, { url: targetURL.href, width, height });
+		(<BrowserWindow>frame.window.parent) = parentWindow;
+		(<BrowserWindow>frame.window.top) = topWindow;
 		(<number>frame.window.devicePixelRatio) = devicePixelRatio;
 
 		if (referrer) {
diff --git a/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementNamedNodeMap.ts b/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementNamedNodeMap.ts
index 28a8be90..ce55262a 100644
--- a/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementNamedNodeMap.ts
+++ b/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementNamedNodeMap.ts
@@ -46,8 +46,14 @@ export default class HTMLIFrameElementNamedNodeMap extends HTMLElementNamedNodeM
 	public override setNamedItem(item: Attr): Attr | null {
 		const replacedAttribute = super.setNamedItem(item);
 
+		if (item[PropertySymbol.name] === 'srcdoc') {
+			this.#pageLoader.loadPage();
+		}
+
+		// If the src attribute and the srcdoc attribute are both specified together, the srcdoc attribute takes priority.
 		if (
 			item[PropertySymbol.name] === 'src' &&
+			this[PropertySymbol.ownerElement][PropertySymbol.attributes]['srcdoc']?.value === undefined &&
 			item[PropertySymbol.value] &&
 			item[PropertySymbol.value] !== replacedAttribute?.[PropertySymbol.value]
 		) {
@@ -70,6 +76,21 @@ export default class HTMLIFrameElementNamedNodeMap extends HTMLElementNamedNodeM
 		return replacedAttribute || null;
 	}
 
+	/**
+	 * @override
+	 */
+	public override [PropertySymbol.removeNamedItem](name: string): Attr | null {
+		const removedItem = super[PropertySymbol.removeNamedItem](name);
+		if (
+			removedItem &&
+			(removedItem[PropertySymbol.name] === 'srcdoc' || removedItem[PropertySymbol.name] === 'src')
+		) {
+			this.#pageLoader.loadPage();
+		}
+
+		return removedItem;
+	}
+
 	/**
 	 *
 	 * @param tokens
diff --git a/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementPageLoader.ts b/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementPageLoader.ts
index 6783a5f6..c690a8de 100644
--- a/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementPageLoader.ts
+++ b/packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameElementPageLoader.ts
@@ -19,6 +19,7 @@ export default class HTMLIFrameElementPageLoader {
 	#contentWindowContainer: { window: BrowserWindow | CrossOriginBrowserWindow | null };
 	#browserParentFrame: IBrowserFrame;
 	#browserIFrame: IBrowserFrame;
+	#srcdoc: string | null = null;
 
 	/**
 	 * Constructor.
@@ -44,15 +45,43 @@ export default class HTMLIFrameElementPageLoader {
 	 */
 	public loadPage(): void {
 		if (!this.#element[PropertySymbol.isConnected]) {
-			if (this.#browserIFrame) {
-				BrowserFrameFactory.destroyFrame(this.#browserIFrame);
-				this.#browserIFrame = null;
-			}
-			this.#contentWindowContainer.window = null;
+			this.unloadPage();
 			return;
 		}
 
+		const srcdoc = this.#element.getAttribute('srcdoc');
 		const window = this.#element[PropertySymbol.ownerDocument][PropertySymbol.ownerWindow];
+
+		if (srcdoc !== null) {
+			if (this.#srcdoc === srcdoc) {
+				return;
+			}
+
+			this.unloadPage();
+
+			this.#browserIFrame = BrowserFrameFactory.createChildFrame(this.#browserParentFrame);
+			this.#browserIFrame.url = 'about:srcdoc';
+
+			this.#contentWindowContainer.window = this.#browserIFrame.window;
+
+			(<BrowserWindow>this.#browserIFrame.window.top) = this.#browserParentFrame.window.top;
+			(<BrowserWindow>this.#browserIFrame.window.parent) = this.#browserParentFrame.window;
+
+			this.#browserIFrame.window.document.open();
+			this.#browserIFrame.window.document.write(srcdoc);
+
+			this.#srcdoc = srcdoc;
+
+			this.#element[PropertySymbol.ownerDocument][PropertySymbol.ownerWindow].requestAnimationFrame(
+				() => this.#element.dispatchEvent(new Event('load'))
+			);
+			return;
+		}
+
+		if (this.#srcdoc !== null) {
+			this.unloadPage();
+		}
+
 		const originURL = this.#browserParentFrame.window.location;
 		const targetURL = BrowserFrameURL.getRelativeURL(this.#browserParentFrame, this.#element.src);
 
@@ -105,5 +134,6 @@ export default class HTMLIFrameElementPageLoader {
 			this.#browserIFrame = null;
 		}
 		this.#contentWindowContainer.window = null;
+		this.#srcdoc = null;
 	}
 }
diff --git a/packages/happy-dom/test/nodes/html-iframe-element/HTMLIFrameElement.test.ts b/packages/happy-dom/test/nodes/html-iframe-element/HTMLIFrameElement.test.ts
index 74d75024..79de967c 100644
--- a/packages/happy-dom/test/nodes/html-iframe-element/HTMLIFrameElement.test.ts
+++ b/packages/happy-dom/test/nodes/html-iframe-element/HTMLIFrameElement.test.ts
@@ -35,7 +35,7 @@ describe('HTMLIFrameElement', () => {
 		});
 	});
 
-	for (const property of ['src', 'allow', 'height', 'width', 'name', 'srcdoc']) {
+	for (const property of ['src', 'allow', 'height', 'width', 'name']) {
 		describe(`get ${property}()`, () => {
 			it(`Returns the "${property}" attribute.`, () => {
 				element.setAttribute(property, 'value');
@@ -126,6 +126,105 @@ describe('HTMLIFrameElement', () => {
 		});
 	});
 
+	describe('get srcdoc()', () => {
+		it('Returns string', () => {
+			expect(element.srcdoc).toBe('');
+			element.srcdoc = '<div></div>';
+			expect(element.getAttribute('srcdoc')).toBe('<div></div>');
+		});
+	});
+
+	describe('set srcdoc()', () => {
+		it("Navigate the element's browsing context to a resource whose Content-Type is text/html", async () => {
+			const actualHTML = await new Promise((resolve) => {
+				element.srcdoc = '<div>TEST</div>';
+				element.addEventListener('load', () => {
+					resolve(element.contentDocument?.documentElement.innerHTML);
+				});
+				document.body.appendChild(element);
+			});
+			expect(actualHTML).toBe('<head></head><body><div>TEST</div></body>');
+		});
+
+		it('Takes priority, when the src attribute and the srcdoc attribute are both specified together', async () => {
+			const browser = new Browser();
+			const page = browser.newPage();
+			const window = page.mainFrame.window;
+			const document = window.document;
+			const element = <HTMLIFrameElement>document.createElement('iframe');
+			const url = await new Promise((resolve) => {
+				element.srcdoc = '<html><head></head><body>TEST</body></html>';
+				element.src = 'https://localhost:8080/iframe.html';
+				element.addEventListener('load', () => {
+					resolve(page.mainFrame.childFrames[0].url);
+				});
+				document.appendChild(element);
+			});
+			expect(url).toBe('about:srcdoc');
+		});
+
+		it('Resolve the value of the src attribute when the srcdoc attribute has been removed', async () => {
+			const browser = new Browser();
+			const page = browser.newPage();
+			const window = page.mainFrame.window;
+			const document = window.document;
+			const element = <HTMLIFrameElement>document.createElement('iframe');
+			page.mainFrame.url = 'https://localhost:8080';
+			const responseHTML = '<html><head></head><body>Test</body></html>';
+
+			vi.spyOn(BrowserWindow.prototype, 'fetch').mockImplementation((url: IRequestInfo) => {
+				return Promise.resolve(<Response>(<unknown>{
+					text: () => Promise.resolve(responseHTML),
+					ok: true,
+					headers: new Headers()
+				}));
+			});
+			const frameUrl = 'https://localhost:8080/iframe.html';
+			const actualFrameUrl = await new Promise((resolve) => {
+				element.srcdoc = responseHTML;
+				element.src = frameUrl;
+				const firstLoad = (): void => {
+					expect(page.mainFrame.childFrames[0].url).toBe('about:srcdoc');
+					element.removeEventListener('load', firstLoad);
+					element.addEventListener('load', () => {
+						resolve(page.mainFrame.childFrames[0].url);
+					});
+					element.removeAttribute('srcdoc');
+				};
+				element.addEventListener('load', firstLoad);
+				document.body.appendChild(element);
+			});
+			expect(actualFrameUrl).toBe(frameUrl);
+		});
+
+		it('Execute code in the script', async () => {
+			const message = await new Promise((resolve) => {
+				element.srcdoc = `<!doctype html><html><head>
+				<script>
+				function handleMessage(e) {
+					parent.postMessage({ msg: 'loaded' }, '*');
+				}
+				window.addEventListener('message', handleMessage, false);
+				</script>
+				</head><body></body></html>`;
+				element.addEventListener('load', () => {
+					element.contentWindow?.postMessage('MESSAGE', '*');
+				});
+				window.addEventListener(
+					'message',
+					(e) => {
+						const data = (<MessageEvent>e).data;
+						resolve(data);
+					},
+					false
+				);
+				document.body.appendChild(element);
+				expect(element.contentWindow?.parent === window).toBe(true);
+			});
+			expect(message).toMatchObject({ msg: 'loaded' });
+		});
+	});
+
 	describe('get contentWindow()', () => {
 		it('Returns content window for "about:blank".', () => {
 			element.src = 'about:blank';
@@ -421,6 +520,36 @@ describe('HTMLIFrameElement', () => {
 				document.body.appendChild(element);
 			});
 		});
+
+		it('Remain at the initial about:blank page when none of the srcdoc/src attributes are set', async () => {
+			const browser = new Browser();
+			const page = browser.newPage();
+			const window = page.mainFrame.window;
+			const document = window.document;
+			const element = <HTMLIFrameElement>document.createElement('iframe');
+			page.mainFrame.url = 'https://localhost:8080';
+
+			vi.spyOn(BrowserWindow.prototype, 'fetch').mockImplementation((url: IRequestInfo) => {
+				return Promise.resolve(<Response>(<unknown>{
+					text: () => Promise.resolve('<html><head></head><body>Test</body></html>'),
+					ok: true,
+					headers: new Headers()
+				}));
+			});
+			const actualFrameUrl = await new Promise((resolve) => {
+				element.src = 'https://localhost:8080/iframe.html';
+				const firstLoad = (): void => {
+					element.removeEventListener('load', firstLoad);
+					element.addEventListener('load', () => {
+						resolve(page.mainFrame.childFrames[0].url);
+					});
+					element.removeAttribute('src');
+				};
+				element.addEventListener('load', firstLoad);
+				document.body.appendChild(element);
+			});
+			expect(actualFrameUrl).toBe('about:blank');
+		});
 	});
 
 	describe('get contentDocument()', () => {
@@ -428,6 +557,7 @@ describe('HTMLIFrameElement', () => {
 			element.src = 'about:blank';
 			expect(element.contentDocument).toBe(null);
 			document.body.appendChild(element);
+			expect(element.contentWindow?.parent === window).toBe(true);
 			expect(element.contentDocument?.documentElement.innerHTML).toBe('<head></head><body></body>');
 		});
 	});