The effect of dietary carotenoid from red chilli oleoresin and synthetic astaxanthin on the pigmentation of fresh and minced fillet of rainbow trout was compared. Five experimental diets were evaluated: a control diet (CD) containing 80 mg synthetic astaxanthin (Carophyll Pink 8%) kg −1 diet, two diets containing 80 mg carotenoid kg −1 diet (HRL 1 , HRL 2 ), and two diets containing 120 mg carotenoid kg −1 diet (HRH 1 , HRH 2 ), each paired with low and high carotenoid containing diets from red chilli oleoresins containing different carotenoid composition and concentration, respectively. The six-week experiment was carried out in a closed recirculation system consisting of ten 3.0 m 3 circular tanks containing 161 (150±14 g) rainbow trout. The trout were fed daily at 3% of their total biomass. Results indicated that significant differences existed between fresh and minced fillet colour. Diet HRH 2 showed the least colour difference between the fresh and minced fillets, suggesting that the incorporation of 120 mg carotenoid from red chilli oleoresin kg −1 diet allowed for processing of fillets without significant colour loss. All of the diets produced carotenoid concentrations in trout muscle of more than 5 mg carotenoid kg −1 muscle at the end of the experimental trial. Colour parameters and carotenoid concentrations in muscle were linearly related.