SMEDDS is mixture of oils, surfactants, and cosurfactants, which are emulsified in aqueous media under conditions of gentle agitation and digestive motility that would be encountered in the gastro-intestinal(GI) tract. The main purpose of this work is to prepare self-microemulsifying drug delivery system(SMEDDS) for oral bioavailability enhancement of a poorly water soluble drug, atorvastatin calcium. Solubility of atorvastatin calcium was determined in various vehicles. Pseudo-ternary phase diagrams were constructed to identity the efficient self-emulsification region and particle size distributions of the resultant micro emulsions were determined using a laser diffraction sizer. Optimized formulations for in vitro dissolution and bioavailability assessment were $Capryol^{(R)}$ 90(50%), Tetraglycol(16%), and $Cremophor^{(R)}$ EL(32%). The release rate of atorvastatin from SMEDDS was significantly higher than the conventional tablet ($Lipitor^{(R)}$), 2-fold. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as atorvastatin calcium by the oral route.