The effect of animal maturity on fiber cross-sectional area, percentage of fiber types, isocitrate dehydrogenase (ICDH) and lactate dehydrogenase (LDH) activity, total and insoluble collagen and lipid concentration in the Longissimus thoracis (LT), Semitendinosus (ST) and Triceps brachii (TB) muscles was investigated. The analysis considered 2642 muscle samples from bulls, steers and cows of Aubrac, Charolais, Limousin, Montbéliard and Salers breeds. For the bulls, the fiber cross-sectional area, percentage of slow oxidative fibers and ICDH activity showed a quadratic relationship (P < 0.05) and the percentage of fast oxidative-glycolytic and fast glycolytic fibers and LDH activity a cubic relationship (P < 0.05) with increased maturity. A linear relationship was observed for the collagen and lipid muscle characteristics. The response equation coefficients for different muscles indicate that the development of muscle characteristics is different for each muscle. Compared with the other muscles, ST muscle had a greater fiber cross-sectional area, proportion of fast glycolytic fibers, LDH activity and collagen content and LT muscle had a greater proportion of slow-oxidative fibers and lipid (P < 0.05). Within the ST muscle, all characteristics except the lipid concentration showed different development between the breeds. Steers showed greater changes in muscle fiber cross-sectional area, percentage of fast oxidative-glycolytic and fast glycolytic fibers and total lipid in the muscle with increasing maturity compared with bulls. The mean fiber cross-sectional area and percentage of fast glycolytic fibers was greater and the mean lipid concentration was less in bulls compared with steers (P < 0.05). Data for cows was from more mature animals. Muscle characteristics in cows did not show large changes with degree of maturity. Muscle type accounts for a greater proportion of the variation in the muscle characteristics than breed and sex of the animal.