Adipocyte size and the activity of lipogenic enzymes Glycerol 3‑phosphate dehydrogenase (G3PDH), Fatty acid synthetase (FAS). Glucose 6‑phosphate dehydrogenase (G6PDH) and NADP‑Malate dehydrogenase (EM) in omental (OM), perirrenal (PR), subcutaneous (SC) and intermuscular (IM) adipose depots were studied in 21 fighting bulls that were slaughtered in Pamplona in 1995. The 10th rib from the left half of the carcass was dissected and the amount of intramuscular fat in the Longissimus dorsi muscle was determined, estimating the carcass fatness. Results of amount of fat in the 10th rib (19 p.100) and amount of intramuscular chemical fat in Longissimus dorsi muscle (1 p.100) showed a medium‑low carcass fattening in fighting bulls. Adipocytes from PR adipose depot were the biggest, followed by adipocytes from OM, SC and IM adipose depots (P<0.001). In general the activity of the enzyme G3PDH, which estimates triglyceride synthesis, followed the same pattern (P<0.001). Furthermore, the activities of the enzymes G6PDH and ICDH, which produce the NADPH needed for fatty acid synthesis, also showed a similar pattern to G3PDH (P<0.001). Data obtained in this study were compared with those found in literature referring to cattle, pointing out lower lipogenic activities in fighting bulls than in fattening steers. This observation would conflict with the generally accepted idea that farmers overfeed the bulls during the previous months to the fighting of the bulls.