diff --git a/src/calibre/gui2/tweak_book/completion/basic.py b/src/calibre/gui2/tweak_book/completion/basic.py
index 824e88db53..b0d4df6079 100644
--- a/src/calibre/gui2/tweak_book/completion/basic.py
+++ b/src/calibre/gui2/tweak_book/completion/basic.py
@@ -77,6 +77,7 @@ def complete_names(names_data, data_conn):
         names_cache['stylesheet'] = frozenset(n for n in all_names if n.mime_type in OEB_STYLES)
         names_cache['image'] = frozenset(n for n in all_names if n.mime_type.startswith('image/'))
         names_cache['font'] = frozenset(n for n in all_names if n.mime_type in OEB_FONTS)
+        names_cache['css_resource'] = names_cache['image'] | names_cache['font']
         names_cache['descriptions'] = d = {}
         for x, desc in {'text_link':_('Text'), 'stylesheet':_('Stylesheet'), 'image':_('Image'), 'font':_('Font')}.iteritems():
             for n in names_cache[x]:
diff --git a/src/calibre/gui2/tweak_book/editor/smarts/css.py b/src/calibre/gui2/tweak_book/editor/smarts/css.py
index e7cd826d2c..c0c99ddba0 100644
--- a/src/calibre/gui2/tweak_book/editor/smarts/css.py
+++ b/src/calibre/gui2/tweak_book/editor/smarts/css.py
@@ -6,8 +6,11 @@ from __future__ import (unicode_literals, division, absolute_import,
 __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
 
+import re
+
 from PyQt5.Qt import Qt
 
+from calibre.gui2.tweak_book import current_container
 from calibre.gui2.tweak_book.editor.smarts import NullSmarts
 from calibre.gui2.tweak_book.editor.smarts.utils import (
     no_modifiers, get_leading_whitespace_on_block, get_text_before_cursor,
@@ -33,6 +36,12 @@ def find_rule(raw, rule_address):
 
 class Smarts(NullSmarts):
 
+    def __init__(self, *args, **kwargs):
+        if not hasattr(Smarts, 'regexps_compiled'):
+            Smarts.regexps_compiled = True
+            Smarts.complete_attr_pat = re.compile(r'''url\s*\(\s*['"]{0,1}([^)]*)$''')
+        NullSmarts.__init__(self, *args, **kwargs)
+
     def handle_key_press(self, ev, editor):
         key = ev.key()
 
@@ -65,4 +74,14 @@ class Smarts(NullSmarts):
 
         return False
 
-
+    def get_completion_data(self, editor, ev=None):
+        c = editor.textCursor()
+        c.movePosition(c.StartOfLine, c.KeepAnchor)
+        text = c.selectedText()
+        m = self.complete_attr_pat.search(text)
+        if m is None:
+            return
+        query = m.group(1) or ''
+        doc_name = editor.completion_doc_name
+        if doc_name:
+            return 'complete_names', ('css_resource', doc_name, current_container().root), query