Forty eight Californian ] New Zealand White rabbits were randomly distributed in three groups of 16 animals each. A control (with no added fat) and two diets enriched at a rate of 30 g fat kg~1 were used. Olive oil and sunÑower oil were used as sources of fat for the fat-supplemented diets. Branched chain (BCFA) and n-odd-numbered carbon fatty acids (ONFA) in the perirenal fat depots of control animals were respectively 5 and 22 mg g~1 of total fatty acids, while in fat-enriched diets they were around 3 and 16 mg g~1, respectively. The ratio of unsaturated : saturated fatty acid in perirenal fat was 1É25 : 1 when the control diet was administered and around 1É80È1É95 : 1 in fat-enriched diet groups, which represents approximately a 50% increase (P \ 0É01). However the melting points of the fats showed little di †erence (NS) between the control group and the group with olive oil addition whilst the sunÑower oil-supplemented group showed only a 5É7% lower value (P \ 0É01). In a second experiment in which diets with equal digestible energy and protein were used, reductions in total amounts of ONFA (P \ 0É01) and BCFA (P \ 0É05) were observed in the perirenal fat of animals receiving the fat-enriched diets. The addition of fat depressed the concentrations of ONFA and BCFA, which may act to maintain the consistency of fat in a narrow range, avoiding to some extent the production of undesirable soft and Ñoppy carcasses.