According to a factorial design that observed two commercial sire line of the Duroc breed: M (lean) and G (fat), and two genders (castrated males vs females), 43 Duroc x (Landrace x Large White) pigs were used. The growing-finishing period lasted from 22,50 to 125,16 kg of live weight and all animals were given the same feed during such period. The pigs from G line consumed more feed than those from M line. Castrated males had greater feed intake and average daily gain than females. The pigs from G line showed higher values of ham perimeter, fat thickness at the level of the 10th rib and Biceps femoris muscle. The fat thickness at the level of the 10th rib was higher in castrated males than in females. The rejected percentage of female carcasses in the slaughter-house was higher in females than in castrated males. The sire line had no effect on moisture, protein and intramuscular fat percentages of Longissimus dorsi muscle. However, the loin pH, measured 45 min after slaughter, was higher in pigs from M line than in those from G line. Castrated males had more intramuscular fat percentage than females. The pigs from G line had higher C10:0, C15:1, C16:0 and total saturated fatty acids, and lower C20:3 n-9 and C20:4 n- 6 proportions than those from M line. Castrated males had higher C14:0, C16:1, C18:1n-9 and total monounsatureted fatty acids and lower C18:2 n-6 and total polyunsaturated and n-6 fatty acids proportions than females. The intramuscular fat percentage affected to C14:0, C16:0, C17:0, C18:1n-9, C18:2 n-6, C20:1, C20:4 n-6, total saturated, monounsaturated, polyunsaturated, n-6 proportions and ⅀ n-6/⅀ n-3 and ⅀ POLI/ ⅀ SAT ratios detected in intramuscular fat. It is concluded that the use of a G sire line has not negative effect on productive performance, increases lightly the carcass fatness and saturates the intramuscular fat. Castrated males show more adequate carcasses than females to Teruel ham production.