The aim of the current study was to design oral controlled release matrix tablets of losartan potassium. Tablets were prepared by direct compression and evaluated for hardness, friability, thickness, drug content and in vitro dissolution parameters. Carbopol 934P and HPMC K 100M (hydroxyl propyl methyl cellulose) were used as the polymers . In vitro release studies were conducted in phosphate buffer pH 6.8 for 24 hours. All the formulations showed controlled release of losartan potassium over a period of 24 hours. The release profile of losartan potassium from all the formulations (except F2, F3, F8 which showed first order release) are close to zero order and follow diffusion dependent release. Irrespective of the polymer type and its concentration, the prepared hydrophilic matrix tablets showed non-fickian (anomalous) release, coupled diffusion and polymer matrix relaxation as the values of release exponent (n) are in between 0.584 and 0.8692. Finally it was clear that HPMC K100M and Carbopol 934P are good candidates for preparing controlled release matrix tablets of losartan potassium.