Disclosed herein is a transdermal delivery system comprising methylphenidate or its salt as an active ingredient. Also provided are methods of delivering a therapeutically effective amount of methylphenidate to a subject for the treatment of a disease condition. The disease condition includes a neurological condition such as Attention Deficit Disorder (ADD) and/or Attention Deficit/Hyperactivity Disorder (ADHD). Kits including the transdermal delivery system and methods of making and using the transdermal delivery system are also provided.