Processes for the enzyme-catalyzed synthesis of triglycerides containing polyunsaturated fatty acids in which the synthesis is preceded by a pre-hydrolysis in which (a) C1-4 alkyl esters of polyunsaturated fatty acids are completely or partly hydrolyzed in vacuo with continuous addition of water or are partly hydrolyzed in several stages without vacuum, (b) after the hydrolysis, the water is removed by separation or distillation and (c) the synthesis of the polyunsaturated fatty acids with glycerol in vacuo in the presence of an enzyme to form their triglycerides is carried out under low-water conditions, (d) the enzymes are removed from the triglyceride by separation or filtration and (e) the remaining fatty acids and/or possible residues of C1-4 alkyl esters are removed from the triglyceride by distillation or refining; the pre-hydrolysis and the subsequent synthesis preferably being carried out as a one-pot process in the same reactor and in the presence of the same enzyme.