Intramuscular connective tissue plays an important role in meat tenderness. Our objective was to compare the collagen/hydroxyproline content and X-ray computed tomographic (CT) connective tissue proportion of longissimus thoracis (LT) muscle in Hungarian Simmental bulls and cows. Cows had lower carcass weight (247 kg v. 295 kg), EU conformation score (3.5 v. 5.5) and fatness score (4.2 v. 5.9) than bulls (P<0.01). Bulls had higher LT area, but intramuscular fat content was similar for bulls and cows. On the other hand, bulls had lower CT intramuscular connective tissue proportion in LT compared with cows (0.41±0.21% v. 0.66±0.28%, P<0.01). The same tendency could be observed for the collagen content (0.50±0.21% v. 0.67±0.11%, P<0.01). Correlation between the CT connective tissue proportion of LT and collagen content was r=0.8. There was a weak positive correlation between slaughter age and CT connective tissue as well as collagen content of LT (r=0.3 to 0.4). In conclusion, intramuscular connective tissue proportion in LT increased with slaughter age and older cows had higher collagen and connective tissue proportion than bulls. Mixed CT scans can be used for the analysis of intramuscular connective tissue content.