In this paper, we describe a method to obtain a relatively pure mitochondrial and microsomal fractions by subcellular fractionation of human hepatoma cell line C3A using sucrose as the hypoosmotic medium. The cells were subjected to osmotic stress with sucrose and homogenized. Osmolarity was then restored to the cells and the organelles were separated by density gradient centrifugation. The protein profiles were examined by SDS-PAGE and the purity was analysed by marker enzymes and Western blotting. Our results indicate a good separation of mitochondrial and microsomal fractions from human hepatoma C3A cells.