The aim of the current study was to design sustained release matrix tablets of olanzapine(OLZ) for the treatment of schizophrenia. The tablets were prepared by wet granulation method using glyceryl behenate and HPMC K4M polymer as release retardant polymer. All the batches were evaluated for pre compression parameters and post compression parameters. Hydrophilic matrix of glyceryl behenate alone could not control the olanzapine release effectively for 12 hr whereas when combined with HPMC K4M could slow down the release of drug and can be successfully employed for formulating sustained-release matrix tablets.The dosage regimen of olanzapine is 10mg tablet once in a day. Olanzapine was chosen as a model drug with an aim to develop a sustained release system for a period of 12 hrs. The tablet formulation containing 140mg of glyceryl behenate and 26mg of HPMCK4M considered as overall best formulation (with an in vitro release of 98.13%).This sustained release system was found to deliver olanzapine at a zero-order rate for 12 hrs. Short term stability study (at 40±2ºC/ 75±5% RH for three months) on the best formulation indicated that there no significant changes in drug content. IR spectroscopic study indicated that there are no drug excipient interactions.