diff --git a/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/ComboBoxTests.cs b/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/ComboBoxTests.cs
index f5b341abc6b..f19a5bbd2af 100644
--- a/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/ComboBoxTests.cs
+++ b/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/ComboBoxTests.cs
@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Text;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -36,102 +35,5 @@ await RunSingleControlTestAsync<ComboBox>((form, comboBox) =>
                 return Task.CompletedTask;
             });
         }
-
-        [WinFormsFact]
-        public async Task ComboBox_Select_Item_By_UpArrowKeyAsync()
-        {
-            int expectedKeyPressesCount = 9;
-            await RunComboBoxTestAsync(async (form, comboBox) =>
-            {
-                StringBuilder stringBuilder = new();
-
-                // Reset EventsCount because the control gets selected right after the creation.
-                comboBox.ResetEventsCount();
-                for (int i = 0; i < expectedKeyPressesCount; i++)
-                {
-                    await Task.Delay(100);
-                    await InputSimulator.SendAsync(
-                        form,
-                        inputSimulator => inputSimulator.Keyboard
-                        .Sleep(100)
-                        .KeyPress(WindowsInput.Native.VirtualKeyCode.UP));
-
-                    await Task.Delay(100);
-                    stringBuilder.AppendLine($"i:{i + 1}, eventsCount:{comboBox.EventsCount}");
-                }
-
-                TestOutputHelper.WriteLine($"{stringBuilder}");
-                Assert.Equal(expectedKeyPressesCount, comboBox.EventsCount);
-            },
-            expectedKeyPressesCount,
-            selectedIndex: 9);
-        }
-
-        [WinFormsFact]
-        public async Task ComboBox_Select_Item_By_DownArrowKeyAsync()
-        {
-            int expectedKeyPressesCount = 9;
-            await RunComboBoxTestAsync(async (form, comboBox) =>
-            {
-                // Reset EventsCount because the control gets selected right after the creation.
-                comboBox.ResetEventsCount();
-                for (int i = 0; i < expectedKeyPressesCount; i++)
-                {
-                    await InputSimulator.SendAsync(
-                        form,
-                        inputSimulator => inputSimulator.Keyboard.KeyPress(WindowsInput.Native.VirtualKeyCode.DOWN));
-
-                    Assert.Equal(i + 1, comboBox.EventsCount);
-                }
-
-                Assert.Equal(expectedKeyPressesCount, comboBox.EventsCount);
-            },
-            expectedKeyPressesCount,
-            selectedIndex: 0);
-        }
-
-        private async Task RunComboBoxTestAsync(Func<Form, ComboBoxWithSelectCounter, Task> runTest, int numberOfItemsToAdd, int selectedIndex)
-        {
-            await RunSingleControlTestAsync(
-                testDriverAsync: runTest,
-                createControl: () =>
-                {
-                    ComboBoxWithSelectCounter control = new();
-                    control.AddItems(numberOfItemsToAdd);
-                    control.SelectedIndex = selectedIndex;
-                    return control;
-                },
-                createForm: () =>
-                {
-                    return new()
-                    {
-                        Size = new(500, 300),
-                    };
-                });
-        }
-
-        private class ComboBoxWithSelectCounter : ComboBox
-        {
-            public int EventsCount { get; private set; }
-
-            public void AddItems(int numToAdd)
-            {
-                for (int i = 0; i <= numToAdd; i++)
-                {
-                    Items.Add($"Item {i}");
-                }
-            }
-
-            protected override void OnSelectedIndexChanged(EventArgs e)
-            {
-                base.OnSelectedIndexChanged(e);
-                EventsCount++;
-            }
-
-            public void ResetEventsCount()
-            {
-                EventsCount = 0;
-            }
-        }
     }
 }
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ComboBoxTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ComboBoxTests.cs
index 1529ef4c9dc..d23c8bb5e56 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ComboBoxTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ComboBoxTests.cs
@@ -2271,6 +2271,31 @@ public void OwnerDrawComboBox_Verify_OnMeasureItem_Receives_Correct_Arguments()
             }
         }
 
+        [WinFormsTheory]
+        [InlineData(Keys.Up, 9, 9)]
+        [InlineData(Keys.Down, 9, 0)]
+        public void ComboBox_Select_Item_By_Key(Keys key, int expectedKeyPressesCount, int selectedIndex)
+        {
+            using ComboBoxWithSelectCounter comboBox = new();
+            comboBox.AddItems(expectedKeyPressesCount+1);
+            comboBox.CreateControl();
+            comboBox.SelectedIndex = selectedIndex;
+            comboBox.ResetEventsCount();
+
+            // https://docs.microsoft.com/windows/win32/inputdev/wm-keyup
+            // The MSDN page tells us what bits of lParam to use for each of the parameters.
+            // All we need to do is some bit shifting to assemble lParam.
+            nint keyCode = (nint)key;
+            nint lParam = 0x00000001 | keyCode << 16;
+            for (int i = 0; i < expectedKeyPressesCount; i++)
+            {
+                User32.SendMessageW(comboBox, User32.WM.KEYDOWN, keyCode, lParam);
+                User32.SendMessageW(comboBox, User32.WM.KEYUP, keyCode, lParam);
+            }
+
+            Assert.Equal(expectedKeyPressesCount, comboBox.EventsCount);
+        }
+
         private void InitializeItems(ComboBox comboBox, int numItems)
         {
             for (int i = 0; i < numItems; i++)
@@ -2472,6 +2497,15 @@ public void ConfigureForCtrlBackspace(int cursorRelativeToEnd = 0)
         private class ComboBoxWithSelectCounter : ComboBox
         {
             public int EventsCount { get; private set; }
+
+            public void AddItems(int numToAdd)
+            {
+                for (int i = 0; i < numToAdd; i++)
+                {
+                    Items.Add($"Item {i}");
+                }
+            }
+
             protected override void OnSelectedIndexChanged(EventArgs e)
             {
                 base.OnSelectedIndexChanged(e);