diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 5700382e5f..ca40261dea 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -87,7 +87,8 @@ If you intend for any variables/functions/classes to be available outside of the
 #### Unit testing
 MONAI tests are located under `tests/`.
 
-- The unit test's file name follows `test_[module_name].py`.
+- The unit test's file name currently follows `test_[module_name].py` or `test_[module_name]_dist.py`.
+- The `test_[module_name]_dist.py` subset of unit tests requires a distributed environment to verify the module with distributed GPU-based computation.
 - The integration test's file name follows `test_integration_[workflow_name].py`.
 
 A bash script (`runtests.sh`) is provided to run all tests locally.
diff --git a/runtests.sh b/runtests.sh
index 0e87a3a4e5..38f26347bb 100755
--- a/runtests.sh
+++ b/runtests.sh
@@ -46,6 +46,7 @@ doClangFormat=false
 doPytypeFormat=false
 doMypyFormat=false
 doCleanup=false
+doDistTests=false
 
 NUM_PARALLEL=1
 
@@ -53,7 +54,7 @@ PY_EXE=${MONAI_PY_EXE:-$(which python)}
 
 function print_usage {
     echo "runtests.sh [--codeformat] [--autofix] [--black] [--isort] [--flake8] [--clangformat] [--pytype] [--mypy]"
-    echo "            [--unittests] [--coverage] [--quick] [--net] [--dryrun] [-j number] [--clean] [--help] [--version]"
+    echo "            [--unittests] [--disttests] [--coverage] [--quick] [--net] [--dryrun] [-j number] [--clean] [--help] [--version]"
     echo ""
     echo "MONAI unit testing utilities."
     echo ""
@@ -79,6 +80,7 @@ function print_usage {
     echo ""
     echo "MONAI unit testing options:"
     echo "    -u, --unittests   : perform unit testing"
+    echo "    --disttests       : perform distributed unit testing"
     echo "    --coverage        : report testing code coverage, to be used with \"--net\", \"--unittests\""
     echo "    -q, --quick       : skip long running unit tests and integration tests"
     echo "    --net             : perform integration testing"
@@ -232,6 +234,9 @@ do
             doPytypeFormat=true
             doMypyFormat=true
         ;;
+        --disttests)
+            doDistTests=true
+        ;;
         --black)
             doBlackFormat=true
         ;;
@@ -519,6 +524,14 @@ then
     ${cmdPrefix}${cmd} ./tests/runner.py -p "test_((?!integration).)"
 fi
 
+# distributed test only
+if [ $doDistTests = true ]
+then
+    echo "${separator}${blue}run distributed unit test cases${noColor}"
+    torch_validate
+    ${cmdPrefix}${cmd} ./tests/runner.py -p "test_.*_dist$"
+fi
+
 # network training/inference/eval integration tests
 if [ $doNetTests = true ]
 then