This study was conducted to evaluate the effects of diets, including 0.5, 2 and 4.4% dried hot or sweet red pepper and a control diet without added red pepper, on pigmentation, sensory properties and weight gain of rainbow trout, with average initial weight of 60 g, for a rearing period of 80 days. Both red pepper types had similar effects on the carotenoid accumulation, weight gain and sensorial properties of the fish (P>0.05). Total carotenoid accumulation in the fish muscle increased significantly with increasing inclusion of red peppers. However, only the diet consisting of 4.4% hot or sweet red pepper provided adequate carotenoid accumulation in the fillet of the fish, that is, the desired colouration in the fish. Fish fed diets containing red peppers exhibited higher appearance and colour scores compared to control group (P<0.05). Irrespective of being hot or sweet, red pepper can be successfully used as an alternative natural carotenoid source in rainbow trout diets.