diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -199,6 +199,7 @@
     'ComprehensiveLintEngine' => 'lint/engine/ComprehensiveLintEngine.php',
     'GoTestResultParser' => 'unit/engine/GoTestResultParser.php',
     'GoTestResultParserTestCase' => 'unit/engine/__tests__/GoTestResultParserTestCase.php',
+    'KarmaTestEngine' => 'unit/engine/KarmaTestEngine.php',
     'NoseTestEngine' => 'unit/engine/NoseTestEngine.php',
     'PHPUnitTestEngineTestCase' => 'unit/engine/__tests__/PHPUnitTestEngineTestCase.php',
     'PhpunitResultParser' => 'unit/engine/PhpunitResultParser.php',
@@ -367,6 +368,7 @@
     'ComprehensiveLintEngine' => 'ArcanistLintEngine',
     'GoTestResultParser' => 'ArcanistTestResultParser',
     'GoTestResultParserTestCase' => 'ArcanistTestCase',
+    'KarmaTestEngine' => 'ArcanistUnitTestEngine',
     'NoseTestEngine' => 'ArcanistUnitTestEngine',
     'PHPUnitTestEngineTestCase' => 'ArcanistTestCase',
     'PhpunitResultParser' => 'ArcanistTestResultParser',
diff --git a/src/unit/engine/KarmaTestEngine.php b/src/unit/engine/KarmaTestEngine.php
new file mode 100644
--- /dev/null
+++ b/src/unit/engine/KarmaTestEngine.php
@@ -0,0 +1,70 @@
+<?php
+
+/**
+ * Karma wrapper.
+ */
+final class KarmaTestEngine extends ArcanistUnitTestEngine {
+
+  protected function supportsRunAllTests() {
+    // In fact, this is the only mode that `karma` supports.
+    return true;
+  }
+
+  public function run() {
+    $working_copy = $this->getWorkingCopy();
+    $project_root = $working_copy->getProjectRoot();
+    $config_manager = $this->getConfigurationManager();
+
+    $config   = $config_manager->getConfigFromAnySource('unit.karma.config');
+    $junit    = $config_manager->getConfigFromAnySource('unit.karma.junit');
+    $coverage = $config_manager->getConfigFromAnySource('unit.karma.coverage');
+
+    if (!$config) {
+      throw new ArcanistUsageException(
+        'No configuration is configured. Set `unit.karma.config` '.
+        'in your `.arcconfig` file.');
+    }
+
+    if (!$junit) {
+      throw new ArcanistUsageException(
+        'No JUnit output file is configured. Set `unit.karma.junit` '.
+        'in your `.arcconfig` file.');
+    }
+
+    if ($this->getEnableCoverage() && !$coverage) {
+      throw new ArcanistUsageException(
+        'No coverage output file is configured. Set `unit.karma.coverage` '.
+        'in your `.arcconfig` file.');
+    }
+
+    $future = $this->buildTestFuture($config);
+    $future->resolvex();
+
+    return $this->parseTestResults($junit, $coverage);
+  }
+
+  private function buildTestFuture($config) {
+    $flags = array(
+      '--log-level=info',
+      '--no-colors',
+    );
+
+    $reporters = array();
+    $reporters[] = 'junit';
+
+    if ($this->getEnableCoverage()) {
+      $reporters[] = 'coverage';
+    }
+    $flags[] = '--reporters='.implode(',', $reporters);
+
+    $future = id(new ExecFuture('karma start %Ls %s', $flags, $config))
+      ->setCWD($this->getWorkingCopy()->getProjectRoot());
+    return $future;
+  }
+
+  private function parseTestResults($junit) {
+    $parser = new ArcanistXUnitTestResultParser();
+    return $parser->parseTestResults(Filesystem::readFile($junit));
+  }
+
+}