diff --git a/CHANGELOG.md b/CHANGELOG.md
index e1253599..a67fa413 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Added support for multiple isolated processes.
+
 ### Breaking Changes
 
 - None
diff --git a/Readme.md b/Readme.md
index 29e99ff6..9f49d054 100644
--- a/Readme.md
+++ b/Readme.md
@@ -205,7 +205,9 @@ Options are:
           default - runtime when runtime log is filled otherwise filesize
     -m, --multiply-processes [FLOAT] use given number as a multiplier of processes to run
     -s, --single [PATTERN]           Run all matching files in the same process
-    -i, --isolate                    Do not run any other tests in the group used by --single(-s)
+    -i, --isolate                    Do not run any other tests in the group used by --single(-s). 
+                                     Automatically turned on if --isolate-n is set above 0.
+        --isolate-n                  Number of processes for isolated groups. Default to 1 when --isolate is on. 
         --only-group INT[, INT]
     -e, --exec [COMMAND]             execute this code parallel and with ENV['TEST_ENV_NUMBER']
     -o, --test-options '[OPTIONS]'   execute test commands with those options
diff --git a/lib/parallel_tests/cli.rb b/lib/parallel_tests/cli.rb
index 089cd838..c9b0bca8 100644
--- a/lib/parallel_tests/cli.rb
+++ b/lib/parallel_tests/cli.rb
@@ -192,6 +192,12 @@ def parse_options!(argv)
           options[:isolate] = true
         end
 
+        opts.on("--isolate-n [PROCESSES]",
+          Integer,
+          "Use 'isolate'  singles with number of processes, default: 1.") do |n|
+          options[:isolate_count] = n
+        end
+
         opts.on("--only-group INT[, INT]", Array) { |groups| options[:only_group] = groups.map(&:to_i) }
 
         opts.on("-e", "--exec [COMMAND]", "execute this code parallel and with ENV['TEST_ENV_NUMBER']") { |path| options[:execute] = path }
diff --git a/lib/parallel_tests/grouper.rb b/lib/parallel_tests/grouper.rb
index 0db018a7..de0d1bab 100644
--- a/lib/parallel_tests/grouper.rb
+++ b/lib/parallel_tests/grouper.rb
@@ -15,19 +15,46 @@ def in_even_groups_by_size(items, num_groups, options= {})
         groups = Array.new(num_groups) { {:items => [], :size => 0} }
 
         # add all files that should run in a single process to one group
-        (options[:single_process] || []).each do |pattern|
-          matched, items = items.partition { |item, _size| item =~ pattern }
-          matched.each { |item, size| add_to_group(groups.first, item, size) }
+        single_process_patterns = options[:single_process] || []
+
+        single_items, items = items.partition do |item, _size|
+          single_process_patterns.any? { |pattern| item =~ pattern }
         end
 
-        groups_to_fill = (options[:isolate] ? groups[1..-1] : groups)
-        group_features_by_size(items_to_group(items), groups_to_fill)
+        isolate_count = isolate_count(options)
+
+        if isolate_count >= num_groups
+          raise 'Number of isolated processes must be less than total the number of processes'
+        end
+
+        if isolate_count >= 1
+          # add all files that should run in a multiple isolated processes to their own groups
+          group_features_by_size(items_to_group(single_items), groups[0..(isolate_count - 1)])
+          # group the non-isolated by size
+          group_features_by_size(items_to_group(items), groups[isolate_count..-1])
+        else
+          # add all files that should run in a single non-isolated process to first group
+          single_items.each { |item, size| add_to_group(groups.first, item, size) }
+
+          # group all by size
+          group_features_by_size(items_to_group(items), groups)
+        end
 
         groups.map! { |g| g[:items].sort }
       end
 
       private
 
+      def isolate_count(options)
+        if options[:isolate_count] && options[:isolate_count] > 1
+          options[:isolate_count]
+        elsif options[:isolate]
+          1
+        else
+          0
+        end
+      end
+
       def largest_first(files)
         files.sort_by{|_item, size| size }.reverse
       end
diff --git a/spec/parallel_tests/cli_spec.rb b/spec/parallel_tests/cli_spec.rb
index 2eecd202..7be6f4c8 100644
--- a/spec/parallel_tests/cli_spec.rb
+++ b/spec/parallel_tests/cli_spec.rb
@@ -107,6 +107,26 @@ def call(*args)
       end
     end
 
+    context "single and isolate" do
+      it "single_process should be an array of patterns" do
+        expect(call(["test", "--single", '1'])).to eq(defaults.merge(single_process: [/1/]))
+      end
+
+      it "single_process should be an array of patterns" do
+        expect(call(["test", "--single", '1', "--single", '2'])).to eq(defaults.merge(single_process: [/1/, /2/]))
+      end
+
+      it "isolate should set isolate_count defaults" do
+        expect(call(["test", "--single", '1', "--isolate"])).to eq(defaults.merge(single_process: [/1/], isolate: true))
+      end
+
+      it "isolate_n should set isolate_count and turn on isolate" do
+        expect(call(["test", "-n", "3", "--single", '1', "--isolate-n", "2"])).to eq(
+          defaults.merge(count: 3, single_process: [/1/], isolate_count: 2)
+        )
+      end
+    end
+
     context "when the -- option separator is used" do
       it "interprets arguments as files/directories" do
         expect(call(%w(-- test))).to eq( files: %w(test))
diff --git a/spec/parallel_tests/grouper_spec.rb b/spec/parallel_tests/grouper_spec.rb
index d8710d95..ee571a36 100644
--- a/spec/parallel_tests/grouper_spec.rb
+++ b/spec/parallel_tests/grouper_spec.rb
@@ -54,9 +54,22 @@ def call(num_groups, options={})
       expect(call(2, :single_process => [/1|2|3|4/])).to eq([["1", "2", "3", "4"], ["5"]])
     end
 
+    it "groups single items into specified isolation groups" do
+      expect(call(3, :single_process => [/1|2|3|4/], :isolate_count => 2)).to eq([["1", "4"], ["2", "3"], ["5"]])
+    end
+
     it "groups single items with others if there are too few" do
       expect(call(2, :single_process => [/1/])).to eq([["1", "3", "4"], ["2", "5"]])
     end
+
+    it "groups must abort when isolate_count is out of bounds" do
+      expect {
+        call(3, :single_process => [/1/], :isolate_count => 3)
+      }.to raise_error(
+        "Number of isolated processes must be less than total the number of processes"
+      )
+    end
+
   end
 
   describe '.by_scenarios' do
diff --git a/spec/parallel_tests/test/runner_spec.rb b/spec/parallel_tests/test/runner_spec.rb
index 90a6fcf6..34b1778e 100644
--- a/spec/parallel_tests/test/runner_spec.rb
+++ b/spec/parallel_tests/test/runner_spec.rb
@@ -146,6 +146,26 @@ def call(*args)
 
         expect(valid_combinations).to include(actual)
       end
+
+      it "groups by size and use specified number of isolation groups" do
+        skip if RUBY_PLATFORM == "java"
+        expect(ParallelTests::Test::Runner).to receive(:runtimes).
+          and_return({"aaa1" => 1, "aaa2" => 3, "aaa3" => 2, "bbb" => 3, "ccc" => 1, "ddd" => 2})
+        result = call(["aaa1", "aaa2", "aaa3", "bbb", "ccc", "ddd", "eee"], 4, isolate_count: 2, single_process: [/^aaa/], group_by: :runtime)
+
+        isolated_1, isolated_2, *groups = result
+        expect(isolated_1).to eq(["aaa2"])
+        expect(isolated_2).to eq(["aaa1", "aaa3"])
+        actual = groups.map(&:to_set).to_set
+
+        # both eee and ccs are the same size, so either can be in either group
+        valid_combinations = [
+          [["bbb", "eee"], ["ccc", "ddd"]].map(&:to_set).to_set,
+          [["bbb", "ccc"], ["eee", "ddd"]].map(&:to_set).to_set
+        ]
+
+        expect(valid_combinations).to include(actual)
+      end
     end
   end