Biodiesel was produced by transesterification of waste olive oil with methanol and Novozym [R] 435. The effect of the molar ratio of methanol to triolein, mode of methanol addition, reaction temperature, and mixing speed on biodiesel yield was determined. The effect of different acyl acceptors and/or solvents on biodiesel yield was also evaluated. Finally, the efficacy of Novozym[R] 435 was determined by reusing the enzyme after washing it with a solvent. (Contains 9 figures.)