Polyunsatd. fatty acids contained in cod liver oil (initial conch. 39.04%) were concd. by extn. to solid phase (aminopropyl columns, acids-to-packing mass ratio 0.6:100 to 12:100), low-temp. crystn. and complexation with urea to the final concn. ;97.79%, 70.47% and 97.07%, resp. Docosahexaenoic and eicosapentaenoic acids were the main components of the concentrates. The no. of passings of the oil through the extn. column (up to 6) did not influence the conch. efficiency.