--- a/mobile/android/app/mobile.js
+++ b/mobile/android/app/mobile.js
@@ -657,19 +657,16 @@ pref("reader.parse-on-load.enabled", tru
 
 // Force to enable reader mode to parse on loaded a page.
 // Allow reader mode even on low-memory platforms
 pref("reader.parse-on-load.force-enabled", false);
 
 // The default of font size in reader (1-7)
 pref("reader.font_size", 4);
 
-// The default of margin size in reader (5%-25%)
-pref("reader.margin_size", 5);
-
 // The default color scheme in reader (light, dark, sepia, auto)
 // auto = color automatically adjusts according to ambient light level
 pref("reader.color_scheme", "auto");
 
 // The font type in reader (sans-serif, serif)
 pref("reader.font_type", "sans-serif");
 
 // Used to show a first-launch tip in reader

--- a/mobile/android/chrome/content/aboutReader.html
+++ b/mobile/android/chrome/content/aboutReader.html
@@ -26,18 +26,16 @@
     <ul class="dropdown">
       <li><a class="dropdown-toggle button style-button" href="#"></a></li>
       <li class="dropdown-popup">
         <ul id="color-scheme-buttons" class="segmented-button"></ul>
         <hr></hr>
         <ul id="font-type-buttons" class="segmented-button"></ul>
         <hr></hr>
         <div id="font-size-control" class="step-control"></div>
-        <hr></hr>
-        <div id="margin-size-control" class="step-control"></div>
       </li>
     </ul>
     <li><a id="list-button" class="button list-button" href="#"></a></li>
     <li><a id="toggle-button" class="button toggle-button" href="#"></a></li>
   </ul>
 
 </body>
 

--- a/mobile/android/chrome/content/aboutReader.js
+++ b/mobile/android/chrome/content/aboutReader.js
@@ -86,22 +86,16 @@ let AboutReader = function(doc, win) {
   this._setFontType(fontType);
 
   let fontTitle = gStrings.GetStringFromName("aboutReader.textTitle");
   this._fontSize = 0;
   this._setupStepControl("font-size-control", fontTitle,
     this._FONT_SIZE_MIN, this._FONT_SIZE_MAX, this._FONT_SIZE_STEP, Services.prefs.getIntPref("reader.font_size"),
     this._onFontSizeChange.bind(this));
 
-  let marginTitle = gStrings.GetStringFromName("aboutReader.marginTitle");
-  this._marginSize = 0;
-  this._setupStepControl("margin-size-control", marginTitle,
-    this._MARGIN_SIZE_MIN, this._MARGIN_SIZE_MAX, this._MARGIN_SIZE_STEP, Services.prefs.getIntPref("reader.margin_size"),
-    this._onMarginSizeChange.bind(this));
-
   dump("Decoding query arguments");
   let queryArgs = this._decodeQueryString(win.location.href);
 
   this._isReadingListItem = (queryArgs.readingList == "1");
   this._updateToggleButton();
 
   let url = queryArgs.url;
   let tabId = queryArgs.tabId;
@@ -113,19 +107,16 @@ let AboutReader = function(doc, win) {
     this._loadFromURL(url);
   }
 }
 
 AboutReader.prototype = {
   _FONT_SIZE_MIN: 1,
   _FONT_SIZE_MAX: 7,
   _FONT_SIZE_STEP: 1,
-  _MARGIN_SIZE_MIN: 5,
-  _MARGIN_SIZE_MAX: 25,
-  _MARGIN_SIZE_STEP: 5,
 
   _BLOCK_IMAGES_SELECTOR: ".content p > img:only-child, " +
                           ".content p > a:only-child > img:only-child, " +
                           ".content .wp-caption img, " +
                           ".content figure img",
 
   get _doc() {
     return this._docRef.get();
@@ -293,28 +284,16 @@ AboutReader.prototype = {
 
     gChromeWin.sendMessageToJava({
       type: "Reader:Share",
       url: this._article.url,
       title: this._article.title
     });
   },
 
-  _onMarginSizeChange: function Reader_onMarginSizeChange(newMarginSize) {
-    let doc = this._doc;
-
-    this._marginSize = newMarginSize;
-    doc.body.style.marginLeft = this._marginSize + "%";
-    doc.body.style.marginRight = this._marginSize + "%";
-
-    this._updateImageMargins();
-
-    Services.prefs.setIntPref("reader.margin_size", this._marginSize);
-  },
-
   _onFontSizeChange: function Reader_onFontSizeChange(newFontSize) {
     let bodyClasses = this._doc.body.classList;
 
     if (this._fontSize > 0)
       bodyClasses.remove("font-size" + this._fontSize);
 
     this._fontSize = newFontSize;
     bodyClasses.add("font-size" + this._fontSize);

--- a/mobile/android/locales/en-US/chrome/aboutReader.properties
+++ b/mobile/android/locales/en-US/chrome/aboutReader.properties
@@ -1,17 +1,16 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 aboutReader.loading=Loading...
 aboutReader.loadError=Failed to load article from page
 
 aboutReader.textTitle=Text
-aboutReader.marginTitle=Margins
 
 aboutReader.colorSchemeLight=Light
 aboutReader.colorSchemeDark=Dark
 aboutReader.colorSchemeSepia=Sepia
 aboutReader.colorSchemeAuto=Auto
 
 aboutReader.fontTypeSansSerif=Sans
 aboutReader.fontTypeSerif=Serif