The objective of the present study is to develop swellable osmotic drug delivery system of Amitriptyline hydrochloride. Amitriptyline hydrochloride is a tricyclic anti depressant widely used for the treatment of depression and neurogenic pain. It is freely soluble in water. In order to achieve controlled release and to improve the bioavailability swellable systems were prepared using hydrophilic polymers hydroxy propyl methyl cellulose (HPMC), sodium carboxy methyl cellulose (SCMC), methyl cellulose (MC) and coated using cellulose acetate. In vitro release studies of different formulations with different orifice diameters were compared. The formulations showed controlled release and good stability during short term accelerated stability studies.