diff --git a/src/vstest.console/CommandLine/Executor.cs b/src/vstest.console/CommandLine/Executor.cs
index 4357c0af3a..225798cd6d 100644
--- a/src/vstest.console/CommandLine/Executor.cs
+++ b/src/vstest.console/CommandLine/Executor.cs
@@ -92,6 +92,8 @@ internal int Execute(params string[] args)
         {
             this.testPlatformEventSource.VsTestConsoleStart();
 
+            var isDiag = args != null && args.Any(arg => arg.StartsWith("--diag", StringComparison.OrdinalIgnoreCase));
+
             // If User specifies --nologo via dotnet, do not print splat screen
             if (args != null && args.Length !=0 && args.Contains("--nologo"))
             {
@@ -100,7 +102,6 @@ internal int Execute(params string[] args)
             }
             else
             {
-                var isDiag = args != null && args.Any(arg => arg.StartsWith("--diag", StringComparison.OrdinalIgnoreCase));
                 this.PrintSplashScreen(isDiag);
             }
 
@@ -114,6 +115,27 @@ internal int Execute(params string[] args)
                 exitCode = 1;
             }
 
+            if (!isDiag)
+            {
+                // This takes a path to log directory and log.txt file. Same as the --diag parameter, e.g. VSTEST_DIAG="logs\log.txt"
+                var diag = Environment.GetEnvironmentVariable("VSTEST_DIAG");
+                // This takes Verbose, Info (not Information), Warning, and Error.
+                var diagVerbosity = Environment.GetEnvironmentVariable("VSTEST_DIAG_VERBOSITY");
+                if (!string.IsNullOrWhiteSpace(diag))
+                {
+                    var verbosity = TraceLevel.Verbose;
+                    if (diagVerbosity != null)
+                    {
+                        if (Enum.TryParse<TraceLevel>(diagVerbosity, ignoreCase: true, out var parsedVerbosity))
+                        {
+                            verbosity = parsedVerbosity;
+                        }
+                    }
+
+                    args = args.Concat(new[] { $"--diag:{diag};TraceLevel={verbosity}" }).ToArray();
+                }
+            }
+
             // Flatten arguments and process response files.
             string[] flattenedArguments;
             exitCode |= this.FlattenArguments(args, out flattenedArguments);