diff --git a/src/Editor.js b/src/Editor.js
index 5468832c..615ebb51 100644
--- a/src/Editor.js
+++ b/src/Editor.js
@@ -155,7 +155,15 @@ var KeyBinding = function(element, host) {
                 return ace.stopEvent(e);
 
             case keys.TAB:
-                host.onTextInput("    ");
+                if (host.hasMultiLineSelection()) {
+                    if (e.shiftKey) {
+                        host.blockOutdent();
+                    } else {
+                        host.blockIndent();
+                    }
+                } else {
+                    host.onTextInput("    ");
+                }
                 return ace.stopEvent(e);
         }
     });
@@ -366,6 +374,38 @@ ace.Editor.prototype.removeLine = function() {
     }
 };
 
+ace.Editor.prototype.blockIndent = function(indentString) {
+    if (!this.hasSelection()) {
+        return;
+    };
+
+    var range = this.getSelectionRange();
+
+    var indentString = indentString || "    ";
+    this.doc.indentRows(range, indentString);
+
+    this.setSelectionAnchor(range.start.row, range.start.column + indentString.length);
+    this._moveSelection(function() {
+        this.moveCursorTo(range.end.row, range.end.column + indentString.length);
+    });
+};
+
+ace.Editor.prototype.blockOutdent = function(indentString) {
+    if (!this.hasSelection()) {
+        return;
+    };
+
+    var range = this.getSelectionRange();
+
+    var indentString = indentString || "    ";
+    var removedColumns = this.doc.outdentRows(range, indentString);
+
+    this.setSelectionAnchor(range.start.row, range.start.column - removedColumns);
+    this._moveSelection(function() {
+        this.moveCursorTo(range.end.row, range.end.column - removedColumns);
+    });
+};
+
 ace.Editor.prototype.onCompositionStart = function() {
     this.renderer.showComposition(this.cursor);
     this.onTextInput(" ");
@@ -625,6 +665,15 @@ ace.Editor.prototype.hasSelection = function() {
     return !!this.selectionLead;
 };
 
+ace.Editor.prototype.hasMultiLineSelection = function() {
+    if (!this.hasSelection()) {
+        return false;
+    }
+
+    var range = this.getSelectionRange();
+    return (range.start.row !== range.end.row);
+};
+
 ace.Editor.prototype.setSelectionAnchor = function(row, column) {
     this.clearSelection();
 
diff --git a/src/TextDocument.js b/src/TextDocument.js
index 85932671..d6b66e75 100644
--- a/src/TextDocument.js
+++ b/src/TextDocument.js
@@ -181,4 +181,28 @@ ace.TextDocument.prototype.replace = function(range, text) {
             : undefined);
 
     return end;
+};
+
+ace.TextDocument.prototype.indentRows = function(range, indentString) {
+  for (var i=range.start.row; i<= range.end.row; i++) {
+      this.lines[i] = indentString + this.getLine(i);
+  }
+  this.fireChangeEvent(range.start.row, range.end.row);
+};
+
+ace.TextDocument.prototype.outdentRows = function(range, indentString) {
+    outdentLength = indentString.length;
+
+    for (var i=range.start.row; i<= range.end.row; i++) {
+        if (this.getLine(i).substr(0, outdentLength) !== indentString) {
+            return 0;
+        }
+    }
+
+    for (var i=range.start.row; i<= range.end.row; i++) {
+        this.lines[i] = this.getLine(i).substring(outdentLength);
+    }
+
+    this.fireChangeEvent(range.start.row, range.end.row);
+    return outdentLength;
 };
\ No newline at end of file
diff --git a/test/TextEditTest.js b/test/TextEditTest.js
index 0a1e5b82..2273995b 100644
--- a/test/TextEditTest.js
+++ b/test/TextEditTest.js
@@ -30,5 +30,48 @@ var TextEditTest = TestCase("TextEditTest",
 
         assertEquals("a\nb", doc.toString());
         assertPosition(1, 0, editor.getCursorPosition());
+    },
+
+    "test: indent block" : function() {
+        var doc = new ace.TextDocument(["a12345", "b12345", "c12345"].join("\n"));
+        var editor = new ace.Editor(doc, new MockRenderer());
+
+        editor.moveCursorTo(1, 3);
+        editor.selectDown();
+
+        editor.blockIndent("    ");
+
+        assertEquals(["a12345", "    b12345", "    c12345"].join("\n"),
+                     doc.toString());
+
+        var selection = editor.getSelectionRange();
+        assertPosition(1, 7, selection.start);
+        assertPosition(2, 7, selection.end);
+    },
+
+    "test: outdent block" : function() {
+        var doc = new ace.TextDocument(["    a12345", "  b12345", "    c12345"].join("\n"));
+        var editor = new ace.Editor(doc, new MockRenderer());
+
+        editor.moveCursorTo(0, 3);
+        editor.selectDown();
+        editor.selectDown();
+
+        editor.blockOutdent("  ");
+        assertEquals(["  a12345", "b12345", "  c12345"].join("\n"),
+                     doc.toString());
+
+        var selection = editor.getSelectionRange();
+        assertPosition(0, 1, selection.start);
+        assertPosition(2, 1, selection.end);
+
+
+        editor.blockOutdent("  ");
+        assertEquals(["  a12345", "b12345", "  c12345"].join("\n"),
+                doc.toString());
+
+        var selection = editor.getSelectionRange();
+        assertPosition(0, 1, selection.start);
+        assertPosition(2, 1, selection.end);
     }
 });
\ No newline at end of file