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Iberian pigs are the ancestral dark-haired pigs of Spain. Currently, they are reared under free range or intensive production systems and sacrificed at 150 to 180 kg BW, and both sexes are castrated. We used 160 Iberian pigs under an intensive system to study the influence of sex (EF, entire females; CF, castrated females; and CM, castrated males) and feeding level (AL, ad libitum; RT, 23% restriction of ad libitum feed intake from 42 to 112 kg) on productive performance and carcass quality at 152 kg BW. There were six treatments (3 × 2) and four replicates (seven pigs) per treatment. From 42 to 152 kg BW, EF tended to eat less (2762 vs. 2902 and 2840 g/d; P ≤ 0.10) than CF or CM but sex did not affect ADG or G:F. From 42 to 112 kg BW, AL fed pigs grew faster than RT pigs (720 vs. 551 g/d; P ≤ 0.001). However, from 112 to 152 kg BW, after the end of the feed restriction period, RT pigs recovered, and ate more feed (3714 vs. 3390 g/d; P ≤ 0.05) and grew faster (822 vs. 655 g/d; P ≤ 0.001) than AL fed pigs. As a result, G:F was better for RT than for AL pigs (P ≤ 0.01). At the end of the trial, RT fed pigs grew less (P ≤ 0.001) than AL fed pigs but G:F was not affected. Carcass yield (P ≤ 0.10) and carcass fat (51.7 vs. 58.2 and 58.9 mm at P2 and 40.9 vs. 49.4 and 49.1 mm at m. Gluteus medius; P ≤ 0.01) were lower and primal cuts yield was higher (43.8 vs. 41.9 and 41.4%; P ≤ 0.001) for EF than for CF or CM. Carcass yield (80.1 vs. 81.0%; P ≤ 0.001) and carcass fat (52.8 vs. 59.8 mm at P2 and 43.2 vs. 49.7 mm at m. Gluteus medius; P ≤ 0.001) were lower but primal cuts yield were higher (42.9 vs. 41.8%; P ≤ 0.05) for RT than for AL fed pigs. The use of EF rather than CF is recommended when Iberian pigs reared under intensive production systems are destined to the dry cured industry. Also, a 23% feed restriction from 42 to 112 kg BW might improve primal cuts yield of pigs at slaughter without jeopardizing gain to feed ratio. [ABSTRACT FROM AUTHOR]