diff --git a/Gruntfile.js b/Gruntfile.js
index 8ffcaeed4..cf8c96242 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -195,6 +195,14 @@ module.exports = function(grunt) {
           specs: 'test/browser/runner-modify-vars-spec.js',
           outfile: 'tmp/browser/test-runner-modify-vars.html'
         }
+      },
+      globalVars: {
+        src: ['test/browser/less/global-vars/*.less'],
+        options: {
+          helpers: 'test/browser/runner-global-vars-options.js',
+          specs: 'test/browser/runner-global-vars-spec.js',
+          outfile: 'tmp/browser/test-runner-global-vars.html'
+        }
       }
     },
 
diff --git a/bin/lessc b/bin/lessc
index 9ee3609a3..9b8b04ce9 100755
--- a/bin/lessc
+++ b/bin/lessc
@@ -25,7 +25,9 @@ var options = {
     relativeUrls: false,
     ieCompat: true,
     strictMath: false,
-    strictUnits: false
+    strictUnits: false,
+    globalVariables: '',
+    modifyVariables: ''
 };
 var continueProcessing = true,
     currentErrorcode;
@@ -53,6 +55,11 @@ var checkBooleanArg = function(arg) {
     return Boolean(onOff[2]);
 };
 
+var parseVariableOption = function(option) {
+    var parts = option.split('=', 2);
+    return '@' + parts[0] + ': ' + parts[1] + ';\n';
+};
+
 var warningMessages = "";
 var sourceMapFileInline = false;
 
@@ -64,7 +71,7 @@ args = args.filter(function (arg) {
         return false;
     }
 
-    if (match = arg.match(/^--?([a-z][0-9a-z-]*)(?:=([^\s]*))?$/i)) { arg = match[1] }
+    if (match = arg.match(/^--?([a-z][0-9a-z-]*)(?:=(.*))?$/i)) { arg = match[1] }
     else { return arg }
 
     switch (arg) {
@@ -189,6 +196,16 @@ args = args.filter(function (arg) {
                 options.strictUnits = checkBooleanArg(match[2]);
             }
             break;
+        case "global-var":
+            if (checkArgFunc(arg, match[2])) {
+                options.globalVariables += parseVariableOption(match[2]);
+            }
+            break;
+        case "modify-var":
+            if (checkArgFunc(arg, match[2])) {
+                options.modifyVariables += parseVariableOption(match[2]);
+            }
+            break;
     }
 });
 
@@ -267,6 +284,8 @@ var parseLessFile = function (e, data) {
         return;
     }
 
+    data = options.globalVariables + data + options.modifyVariables;
+
     options.paths = [path.dirname(input)].concat(options.paths);
     options.filename = input;
 
diff --git a/lib/less/browser.js b/lib/less/browser.js
index 4e1c68cdd..e5a1dce2b 100644
--- a/lib/less/browser.js
+++ b/lib/less/browser.js
@@ -52,6 +52,7 @@ if (dumpLineNumbers) {
 var typePattern = /^text\/(x-)?less$/;
 var cache = null;
 var fileCache = {};
+var varsPre = "";
 
 function log(str, level) {
     if (less.env == 'development' && typeof(console) !== 'undefined' && less.logLevel >= level) {
@@ -294,9 +295,15 @@ function loadStyles(newVars) {
             var env = new less.tree.parseEnv(less),
                 lessText = style.innerHTML || '';
             env.filename = document.location.href.replace(/#.*$/, '');
-            if (newVars) {
+
+            if (newVars || varsPre) {
                 env.useFileCache = true;
-                lessText += "\n" + newVars;
+
+                lessText = varsPre + lessText;
+
+                if (newVars) {
+                    lessText += "\n" + newVars;
+                }
             }
 
             /*jshint loopfunc:true */
@@ -499,6 +506,8 @@ function loadFile(originalHref, currentFileInfo, callback, env, newVars) {
     }
 
     doXHR(href, env.mime, function (data, lastModified) {
+        data = varsPre + data;
+
         // per file cache
         fileCache[href] = data;
 
@@ -518,7 +527,7 @@ function loadStyleSheet(sheet, callback, reload, remaining, newVars) {
     var env = new less.tree.parseEnv(less);
     env.mime = sheet.type;
 
-    if (newVars) {
+    if (newVars || varsPre) {
         env.useFileCache = true;
     }
 
@@ -585,6 +594,18 @@ function initRunningMode(){
     }
 }
 
+function serializeVars(vars) {
+    var s = "";
+
+    for (var name in vars) {
+        s += ((name.slice(0,1) === '@')? '' : '@') + name +': '+
+                ((vars[name].slice(-1) === ';')? vars[name] : vars[name] +';');
+    }
+
+    return s;
+}
+
+
 //
 // Watch mode
 //
@@ -627,12 +648,7 @@ for (var i = 0; i < links.length; i++) {
 // CSS without reloading less-files
 //
 less.modifyVars = function(record) {
-    var newVars = "";
-    for (var name in record) {
-        newVars += ((name.slice(0,1) === '@')? '' : '@') + name +': '+
-                ((record[name].slice(-1) === ';')? record[name] : record[name] +';');
-    }
-    less.refresh(false, newVars);
+    less.refresh(false, serializeVars(record));
 };
 
 less.refresh = function (reload, newVars) {
@@ -659,6 +675,10 @@ less.refresh = function (reload, newVars) {
     loadStyles(newVars);
 };
 
+if (less.globalVars) {
+    varsPre = serializeVars(less.globalVars) + "\n";
+}
+
 less.refreshStyles = loadStyles;
 
 less.Parser.fileLoader = loadFile;
diff --git a/lib/less/lessc_helper.js b/lib/less/lessc_helper.js
index 1581f3e82..be1e5a5c9 100644
--- a/lib/less/lessc_helper.js
+++ b/lib/less/lessc_helper.js
@@ -52,6 +52,8 @@ var lessc_helper = {
         console.log("                           be removed in the future.");
         console.log("  -su=on|off               Allow mixed units, e.g. 1px+1em or 1px*1px which have units");
         console.log("  --strict-units=on|off    that cannot be represented.");
+        console.log("  --global-var='VAR=VALUE' Defines a variable that can be referenced by the file.");
+        console.log("  --modify-var='VAR=VALUE' Modifies a variable already declared in the file.");
         console.log("");
         console.log("-------------------------- Deprecated ----------------");
         console.log("  -O0, -O1, -O2            Set the parser's optimization level. The lower");
diff --git a/test/browser/css/global-vars/simple.css b/test/browser/css/global-vars/simple.css
new file mode 100644
index 000000000..05b9fb02f
--- /dev/null
+++ b/test/browser/css/global-vars/simple.css
@@ -0,0 +1,3 @@
+.test {
+  color: #ff0000;
+}
diff --git a/test/browser/less/global-vars/simple.less b/test/browser/less/global-vars/simple.less
new file mode 100644
index 000000000..00545b164
--- /dev/null
+++ b/test/browser/less/global-vars/simple.less
@@ -0,0 +1,3 @@
+.test {
+  color: @global-var;
+}
diff --git a/test/browser/runner-global-vars-options.js b/test/browser/runner-global-vars-options.js
new file mode 100644
index 000000000..f313b2f77
--- /dev/null
+++ b/test/browser/runner-global-vars-options.js
@@ -0,0 +1,4 @@
+var less = {};
+less.globalVars = {
+  "@global-var": "red"
+};
diff --git a/test/browser/runner-global-vars-spec.js b/test/browser/runner-global-vars-spec.js
new file mode 100644
index 000000000..6dba89170
--- /dev/null
+++ b/test/browser/runner-global-vars-spec.js
@@ -0,0 +1,3 @@
+describe("less.js global vars", function() {
+  testLessEqualsInDocument();
+});