In order to improve the enzymatic production of biodiesel, the reuse of an immobilized preparation of Candida antarctica lipase B (CALB) was assayed under di ff erent conditions. The improvement included: (1) reuse of CALB in the presence of ethanol (EtOH), (2) reuse of CALB in the presence of methanol (MeOH), (3) blended alcohols at di ff erent molar ratios (0:100, 20:80, 40:60, 50:50, 60:40, 80:20 and 100:0, %EtOH:%MeOH), and employing second generation raw materials: waste cooking oil (WCO) and castor oil (CO). When the first strategy was carried out the FAEE (fatty acid ethyl ester) content achieved was 96% in a first cycle but after four cycles the percentage decreased to 32%. For the second strategy the FAME (fatty acid methyl ester) content attained was 63% in a first cycle but after four cycles the percentage was only 13.5%. When the blended alcohols were tested, the negative e ff ect of MeOH was evident for higher concentrations regardless the type of oil used.