diff --git a/HISTORY.md b/HISTORY.md
index 7d20d2f1..25a3c15f 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -6,6 +6,7 @@
   * Added --irb option for the gollum command.
 * Minor Enhancements
   * Support a `:gollum_path` Sinatra setting for `Precious::App`
+  * Add Wiki#size to efficiently count pages without loading them.
 * Bug Fixes
   * Increase minimum Sanitize version requirement to 1.1.0.
     1.0.x versions of Sanitize require Hpricot instead of Nokogiri
diff --git a/lib/gollum/wiki.rb b/lib/gollum/wiki.rb
index 440e967d..25d984f0 100644
--- a/lib/gollum/wiki.rb
+++ b/lib/gollum/wiki.rb
@@ -210,6 +210,17 @@ module Gollum
       tree_list(treeish || 'master')
     end
 
+    # Fill an array with a list of pages.
+    #
+    # ref - A String ref that is either a commit SHA or references one.
+    #
+    # Returns a flat Array of Gollum::Page instances.
+    def size(ref = nil)
+      tree_map_for(ref || 'master').inject(0) do |num, entry|
+        num + (@page_class.valid_page_name?(entry.name) ? 1 : 0)
+      end
+    end
+
     # Public: All of the versions that have touched the Page.
     #
     # options - The options Hash:
diff --git a/test/test_wiki.rb b/test/test_wiki.rb
index a7d065f1..3749e443 100644
--- a/test/test_wiki.rb
+++ b/test/test_wiki.rb
@@ -39,6 +39,10 @@ context "Wiki" do
       pages.map { |p| p.filename }.sort
   end
 
+  test "counts pages" do
+    assert_equal 4, @wiki.size
+  end
+
   test "normalizes commit hash" do
     commit = {:message => 'abc'}
     assert_equal({:message => 'abc', :name => 'Anonymous', :email => 'anon@anon.com'},