To identify more effective but less toxic compositions of organic solvent mixtures for bio-diesel production from Chlorella vulgaris, 15 different organic solvents were examined and compared for their power of lipid extraction from algal biomass. When solvents were individually examined, methanol showed the best efficiency for the extraction of fatty acids, followed by dichloromethane. Although chloroform resulted in yields which were equal to or greater than those of other solvents, it showed a very low fatty acid content and a high level of unknown impurities when analyzed by gas-chromatography (GC). Furthermore, solvent mixtures were applied in order to determine the optimal composition for a high lipid extraction efficiency, using chloroform, methanol and dichloromethane. Through comparison of compositions using the Bligh and Dyers method, the best composition was to be methanol:dichloromethane (1:1). Our findings resulted in a 25% increase of lipid extraction yield, together with C16, C16:2, C18:2 as major components from C. vulgaris. (C) 2013 Elsevier Ltd. All rights reserved.