--- a/browser/components/preferences/in-content-new/tests/browser_permissions_dialog.js
+++ b/browser/components/preferences/in-content-new/tests/browser_permissions_dialog.js
@@ -203,13 +203,35 @@ add_task(async function onPermissionDele
 
   await waitForCondition(() => richlistbox.itemCount == 0);
 
   doc.getElementById("cancel").click();
 
   Assert.equal(SitePermissions.get(URI, "desktop-notification").state,
                SitePermissions.ALLOW,
                "Permission state does not change on clicking cancel");
+
+  SitePermissions.remove(URI, "desktop-notification");
+});
+
+add_task(async function onSearch() {
+  await openPermissionsDialog();
+  let doc = sitePermissionsDialog.document;
+  let richlistbox = doc.getElementById("permissionsBox");
+  let searchBox = doc.getElementById("searchBox");
+
+  SitePermissions.set(URI, "desktop-notification", SitePermissions.ALLOW);
+  searchBox.value = "www.example.com";
+
+  let u = Services.io.newURI("http://www.test.com");
+  SitePermissions.set(u, "desktop-notification", SitePermissions.ALLOW);
+
+  Assert.equal(doc.getElementsByAttribute("origin", "http://www.test.com")[0], null);
+  Assert.equal(doc.getElementsByAttribute("origin", "http://www.example.com")[0],
+               richlistbox.getItemAtIndex(0));
+
+  SitePermissions.remove(URI, "desktop-notification");
+  SitePermissions.remove(u, "desktop-notification");
 });
 
 add_task(async function removeTab() {
   gBrowser.removeCurrentTab();
 });

--- a/browser/components/preferences/sitePermissions.js
+++ b/browser/components/preferences/sitePermissions.js
@@ -19,16 +19,17 @@ var gSitePermissionsManager = {
   _isObserving: false,
   _permissions: new Map(),
   _permissionsToChange: new Map(),
   _permissionsToDelete: new Map(),
   _list: null,
   _bundle: null,
   _removeButton: null,
   _removeAllButton: null,
+  _searchBox: null,
 
   onLoad() {
     let params = window.arguments[0];
     this.init(params);
   },
 
   init(params) {
     if (!this._isObserving) {
@@ -36,25 +37,28 @@ var gSitePermissionsManager = {
       this._isObserving = true;
     }
 
     this._bundle = document.getElementById("bundlePreferences");
     this._type = params.permissionType;
     this._list = document.getElementById("permissionsBox");
     this._removeButton = document.getElementById("removePermission");
     this._removeAllButton = document.getElementById("removeAllPermissions");
+    this._searchBox = document.getElementById("searchBox");
 
     let permissionsText = document.getElementById("permissionsText");
     while (permissionsText.hasChildNodes())
       permissionsText.firstChild.remove();
     permissionsText.appendChild(document.createTextNode(params.introText));
 
     document.title = params.windowTitle;
 
     this._loadPermissions();
+
+    this._searchBox.focus();
   },
 
   uninit() {
     if (this._isObserving) {
       Services.obs.removeObserver(this, "perm-changed");
       this._isObserving = false;
     }
   },
@@ -66,16 +70,19 @@ var gSitePermissionsManager = {
     let permission = subject.QueryInterface(Components.interfaces.nsIPermission);
 
     // Ignore unrelated permission types.
     if (permission.type !== this._type)
       return;
 
     if (data == "added") {
       this._addPermissionToList(permission);
+      if (this._searchBox.value != "") {
+        this.filterPermissionsList();
+      }
     } else if (data == "changed") {
       let p = this._permissions.get(permission.principal.origin);
       p.capability = permission.capability;
       p.capabilityString = this._getCapabilityString(permission.capability);
       this._handleCapabilityChange(p);
     } else if (data == "deleted") {
       this._removePermissionFromList(permission.principal.origin);
     }
@@ -247,9 +254,28 @@ var gSitePermissionsManager = {
     }
 
     for (let p of this._permissionsToDelete.values()) {
       let uri = Services.io.newURI(p.origin);
       SitePermissions.remove(uri, p.type);
     }
     window.close();
   },
+
+  filterPermissionsList() {
+    // Clear old entries.
+    let oldItems = this._list.querySelectorAll("richlistitem");
+    for (let item of oldItems) {
+      item.remove();
+    }
+
+    let keyword = this._searchBox.value.toLowerCase().trim();
+    let permissions = this._permissions;
+    for (let [origin, permission] of permissions) {
+      if (keyword && !origin.includes(keyword)) {
+        continue;
+      }
+
+      this._createPermissionListItem(permission);
+    }
+    this._setRemoveButtonState();
+  },
 };

--- a/browser/components/preferences/sitePermissions.xul
+++ b/browser/components/preferences/sitePermissions.xul
@@ -27,18 +27,18 @@
   <keyset>
     <key key="&windowClose.key;" modifiers="accel" oncommand="window.close();"/>
   </keyset>
 
   <vbox class="contentPane largeDialogContainer" flex="1">
     <description id="permissionsText" control="url"/>
     <separator class="thin"/>
     <hbox align="start">
-      <textbox id="url" flex="1" placeholder="Search Website"
-               type="search"/>
+      <textbox id="searchBox" flex="1" placeholder="&searchbox.placeholder;"
+               type="search" oncommand="gSitePermissionsManager.filterPermissionsList();"/>
     </hbox>
     <separator class="thin"/>
     <richlistbox id="permissionsBox" selected="false"
                  hidecolumnpicker="true" flex="1"
                  onkeypress="gSitePermissionsManager.onPermissionKeyPress(event);"
                  onselect="gSitePermissionsManager.onPermissionSelect();">
       <listheader>
         <treecol id="siteCol" label="&treehead.sitename2.label;" flex="3"

--- a/browser/locales/en-US/chrome/browser/preferences/permissions.dtd
+++ b/browser/locales/en-US/chrome/browser/preferences/permissions.dtd
@@ -21,8 +21,9 @@
 <!ENTITY allow.accesskey              "A">
 <!ENTITY windowClose.key              "w">
 
 <!ENTITY button.cancel.label          "Cancel">
 <!ENTITY button.cancel.accesskey      "C">
 <!ENTITY button.ok.label              "Save Changes">
 <!ENTITY button.ok.accesskey          "S">
 
+<!ENTITY searchbox.placeholder        "Search Website">