The objective of this study was to evaluate the effect of castration on carcass and meat quality traits of Nellore cattle harvested after 0, 100 or 200 days on feed. Thirty-six Nellore calves averaging 256.1 ± 3.05 kg of body weight and 8.2 ± 0.07 months of age were used. Half of the calves were randomly selected for surgical castration one-week prior to weaning. Post-weaning calves were penned and adapted to a common finishing diet. Six bulls and six steers were selected to be harvested after 0, 100 or 200 days on feed. Carcass and meat quality traits were evaluated. Data were analyzed as a completely randomized design with a 2 × 3 factorial arrangement of treatments including two sex conditions and three harvest times. Castration by time on feed interaction was found (P < 0.01) for intramuscular fat and for kidney, pelvic and heart fat. The bull carcasses were heavier (P < 0.05) than those of steer. Regardless of time on feed, castration increased (P < 0.05) backfat thickness. Although unaged meat shear force was similar (P > 0.05) between bulls and steers, castration reduced (P > 0.05) shear force and increased myofibrillar fragmentation index of 14 days aged meat. Castration increased (P < 0.05) postmortem desmin degradation. All carcass traits were improved (P < 0.05) by time on feed, except dressing. Carcasses from cattle harvested at 0 day on feed had higher (P < 0.05) chilling rate and lower pH decline (P < 0.05). Shear force change from 1 to 14 days postmortem reduced (P < 0.05) as time on feed increased. In conclusion, although intensively raised young bulls have similar unaged meat quality than steers, castration improves aged meat tenderness and intramuscular fat. Overall, increasing time on feed improves carcass and meat quality traits.