||The objective of this study is to formulate and evaluate ethyl cellulose microspheres of pioglitazone hydrochloride for sustained/controlled drug release. Ethyl cellulose microspheres loaded with pioglitazone hydrochloride were prepared using emulsion solvent evaporation technique. The prepared microspheres were characterized for their average particle size, drug entrapment efficiency, scanning electron microscopy, DSC studies, in-vitro drug release behavior and in-vitro release mechanism. The microspheres were spherical with average particle size of 19 to 31 μm. The microspheres were free flowing smooth and spherical in shape with ideal surface morphology. The DSC endotherm proves the compatibility of drug and polymer. In-vitro release studies reveals that the microspheres formulation prepared with an increasing concentration of polymer exhibits more control release than the formulation prepared with lower concentration. Among all the batches, formulation with higher concentration of polymer shows an extended release and is suitable for formulate as sustained/controlled delivery system.