Abstract: The present study involves the development of porous osmotic tablets of Venlafaxine Hydrochloride in order to release the drug in sustained and predictable manner. Venlafaxine Hydrochloride is a unique antidepressant that differs structurally from other currently available antidepressants. Short biological half life, low bioavailability and frequent administration of drug led for rational development of 300mg sustained release osmotic tablets of Venlafaxine Hydrochloride that releases the drug and maintain the plasma drug concentration for more than 8hrs. The method of preparation of these SR osmotic tablets follows osmotic bursting pump model. Polymers like hydroxy propyl methyl cellulose (HPMC) K15M with lactose as diluents, magnesium stearate as glidant and talc as lubricant were selected for sustaining the drug release.