Lipase-catalyzed glycerolysis of triolein was studied in a solid-phase system The activity and stability of three bacterial lipases in crude and purified forms were examined. Most of these lipases were suitable for the high-yield synthesis of monooleylglycerol. With crude lipase from Chromobacterium viscosum, 96% monooleylglycerol concentration was achieved. In the case of pure lipase from Pseudomonas cepacia, immobilization on Celite was necessary. This led to a strong increase in the long-term stability and final monooleylglycerol concentration. Immobilization on Sepharose(TX) led to less stable and active lipases from P. cepacia. In general the highest loss in stability was observed in the first reaction hour, and purified lipases were less suitable. Furthermore, sir yeast and mold lipases were employed as catalysts in the model reaction system. Most of them have been neither very stable nor very active in the glycerolysis reaction. Only purified lipase from Rhizopus delemar gave moderate,monooleylglycerol concentrations. The addition of a. delemar at intervals influenced neither stability nor monooleylglycerol concentrations. The optimum cooling temperature for the solidification of the reaction mixture, which was necessary for high monooleylglycerol concentration, was determined to be 8 degrees C.