diff --git a/controller/Async.py b/controller/Async.py
deleted file mode 100644
index 7655c6a..0000000
--- a/controller/Async.py
+++ /dev/null
@@ -1,16 +0,0 @@
-import cherrypy
-
-
-def async( method ):
-  """
-  A decorator for a generator method that causes it to be invoked asynchronously. In other words,
-  whenever a generator method decorated by this decorator is called, its generator is added to
-  the scheduler for later execution.
-
-  This decorator expects a self.scheduler member containing the scheduler to use.
-  """
-  def schedule( self, *args, **kwargs ):
-    thread = method( self, *args, **kwargs )
-    self.scheduler.add( thread )
-  
-  return schedule
diff --git a/controller/Files.py b/controller/Files.py
index bb6828f..ed817d4 100644
--- a/controller/Files.py
+++ b/controller/Files.py
@@ -1,4 +1,5 @@
 import os
+import re
 import cgi
 import time
 import tempfile
@@ -197,6 +198,8 @@ cherrypy._cpcgifs.FieldStorage = FieldStorage
 
 
 class Files( object ):
+  FILE_LINK_PATTERN = re.compile( u'<a\s+href="[^"]*/files/download\?file_id=([^"]+)">', re.IGNORECASE )
+
   """
   Controller for dealing with uploaded files, corresponding to the "/files" URL.
   """
@@ -527,3 +530,29 @@ class Files( object ):
     self.__database.save( db_file )
 
     return dict()
+
+  def purge_unused( self, note ):
+    """
+    Delete files that were linked from the given note but no longer are.
+
+    @type note: model.Note
+    @param note: note to search for file links
+    """
+    # load metadata for all files with the given note's note_id 
+    files = self.__database.select_many( File, File.sql_load_note_files( note.object_id ) )
+    files_to_delete = dict( [ ( db_file.object_id, db_file ) for db_file in files ] )
+
+    # search through the note's contents for current links to files
+    for match in self.FILE_LINK_PATTERN.finditer( note.contents ):
+      file_id = match.groups( 0 )[ 0 ]
+
+      # we've found a link for file_id, so don't delete that file
+      files_to_delete.pop( file_id, None )
+
+    # for each file to delete, delete its metadata from the database and its data from the
+    # filesystem
+    for ( file_id, db_file ) in files_to_delete.items():
+      self.__database.execute( db_file.sql_delete(), commit = False )
+      os.remove( Upload_file.make_server_filename( file_id ) )
+
+    self.__database.commit()
diff --git a/controller/Notebooks.py b/controller/Notebooks.py
index ea21ff5..46d46f3 100644
--- a/controller/Notebooks.py
+++ b/controller/Notebooks.py
@@ -36,7 +36,7 @@ class Notebooks( object ):
   """
   Controller for dealing with notebooks and their notes, corresponding to the "/notebooks" URL.
   """
-  def __init__( self, database, users ):
+  def __init__( self, database, users, files ):
     """
     Create a new Notebooks object.
 
@@ -44,11 +44,14 @@ class Notebooks( object ):
     @param database: database that notebooks are stored in
     @type users: controller.Users
     @param users: controller for all users, used here for updating storage utilization
-    @rtype: Notebooks
+    @type files: controller.Files
+    @param files: controller for all uploaded files, used here for deleting files that are no longer
+                  referenced within saved notes
     @return: newly constructed Notebooks
     """
     self.__database = database
     self.__users = users
+    self.__files = files
 
   @expose( view = Main_page )
   @strongly_expire
@@ -509,6 +512,8 @@ class Notebooks( object ):
 
         new_revision = User_revision( note.revision, note.user_id, user.username )
 
+        self.__files.purge_unused( note )
+
       return new_revision
 
     # if the note is already in the given notebook, load it and update it
diff --git a/controller/Root.py b/controller/Root.py
index e419966..d3f8ee8 100644
--- a/controller/Root.py
+++ b/controller/Root.py
@@ -43,8 +43,8 @@ class Root( object ):
       settings[ u"global" ].get( u"luminotes.payment_email", u"" ),
       settings[ u"global" ].get( u"luminotes.rate_plans", [] ),
     )
-    self.__notebooks = Notebooks( database, self.__users )
     self.__files = Files( database, self.__users )
+    self.__notebooks = Notebooks( database, self.__users, self.__files )
     self.__suppress_exceptions = suppress_exceptions # used for unit tests
 
   @expose( Main_page )
diff --git a/model/File.py b/model/File.py
index 3f620be..c8df6d6 100644
--- a/model/File.py
+++ b/model/File.py
@@ -98,6 +98,18 @@ class File( Persistent ):
   def sql_delete( self ):
     return "delete from file where id = %s;" % quote( self.object_id )
 
+  @staticmethod
+  def sql_load_note_files( note_id ):
+    return \
+      """
+      select
+        file.id, file.revision, file.notebook_id, file.note_id, file.filename, file.size_bytes, file.content_type
+      from
+        file
+      where
+        file.note_id = %s;
+      """ % quote( note_id )
+
   def to_dict( self ):
     d = Persistent.to_dict( self )
     d.update( dict(
diff --git a/model/delta/1.2.0.sql b/model/delta/1.2.0.sql
index c2b46c9..5a2ad05 100644
--- a/model/delta/1.2.0.sql
+++ b/model/delta/1.2.0.sql
@@ -8,3 +8,4 @@ create table file (
   content_type text
 );
 alter table file add primary key ( id );
+create index file_note_id_index on file using btree ( note_id );
diff --git a/model/schema.sql b/model/schema.sql
index a72c9e2..3cc08b6 100644
--- a/model/schema.sql
+++ b/model/schema.sql
@@ -234,6 +234,13 @@ ALTER TABLE ONLY user_notebook
     ADD CONSTRAINT user_notebook_pkey PRIMARY KEY (user_id, notebook_id);
 
 
+--
+-- Name: file_note_id_index; Type: INDEX; Schema: public; Owner: luminotes; Tablespace: 
+--
+
+CREATE INDEX file_note_id_index ON file USING btree (note_id);
+
+
 --
 -- Name: luminotes_user_email_address_index; Type: INDEX; Schema: public; Owner: luminotes; Tablespace: 
 --