The oral rout is an attractive site for the delivery of drugs. Through this route it is possible to carry mucosal (the local effect) and Transmucosal (the systemic effect) drug administration. Within the oral mucosal cavity, the buccal site offers an attractive route of administration for systemic drug delivery. The mucosa has a rich blood supply and it is relatively permeable. Environment of the oral mucosa and the experimental methods used in assessing buccal drug permeation/absorption. The main obstacles that drug meets when administered via buccal route derive from limited absorption area and the barrier properties of the mucosa. It is the objective of this article to review buccal drug delivery by discussing the advantages and limitations of buccal drug delivery, structure and design of buccal dosage forms, mechanism and factors affecting of buccal absorption Buccal dosage forms will also be reviewed with an emphasis on bioadhesive polymeric based delivery systems and methodology in evaluating buccal formulations.