The experiment examined the effect of fish oil in calf diets on the fatty acid profile in the fat of 16 Black-and-White bull calves allotted to 2 groups of 8 animals from 7 to 90 days of age. The animals of the control group were given ad libitum a diet consisting of ground cereals, soyabean meal and minerals supplemented for the experimental group (FO) with 4% of fsh oil. At 90 days of age the calves were slaughtered and samples of meat from Musculus thoracis were analysed for fatty acid content. Differences in total fat appeared to be not significant (P>0.05) between the groups. A significant increase in n-3 FA and decrease in the n-6/n-3 ratio was found in the meat fat of group FO animals. Supplementation of the diet with fish oil increased the proportion of C_20:1 n-9, C_20:4 n-3, C_20:5 n-3, C_22:4 n-6, C_22:5 n-3 and C_22:6 n-3, whereas the proportions of C_18:0 decreased significantly.