MOLT-4 lymphocytes metabolize 13-hydroxy-9,11-octadecadienoic acid, via the beta-oxidation pathway with retention of the omega 6 hydroxyl group and the conjugated diene system. The products which accumulate include 11-hydroxy-7,9-hexadecadienoic acid and 9-hydroxy-5,7-tetradecadienoic acid. In addition, it was possible to isolate two beta-hydroxy acids which were shown to be 3,13-dihydroxy-9,11-octadecadienoic acid and 3,11-dihydroxy-7,9-hexadecadienoic acid. The odd chain aldehyde, 12-hydroxy-8,10-heptadecadien-1-al, also was detected. However, neither the pathway nor the immediate precursor for the synthesis of this compound was established.