Carotenoids represent a very important class of plant pigments being held responsible for the quality parameters of fruit and vegetables. There are more than 700 different carotenoids identified in nature, of which about 40 are included in ordinary human diet and only 14 of them and some of their metabolites are present in blood and tissues. Carotenoids are C40 tetraterpenoid pigments which are present in plants, fungi and bacteria. Depending on the structure, they are classified in: hydrocarbon carotenoids known as carotenes and oxygenated carotenoids known as xanthophyll. The researches carried on these classes of compounds shown that carotenoids provided through the diet induce many beneficial functions in mammals, including humans, attributing their antioxidant activities and their property to generate vitamin A. Due to this properties, carotenoids are considered able to protect against oxidative stress and were investigated in terms of disease prevention and treatment. The color of salmonids is one of their most important quality criteria. The typical pink muscle color is determined by astaxanthin, a carotenoid coming from dietary compounds that fish cannot synthesize. In addition to the pigmentation contribution, carotenoids are important in fish life, contributing for the proper function of some complex biological processes. Most of the time, the color of farmed trout is induced by adding cantaxanthin and astaxanthin which are two synthetic carotenoids, but this process is often too expensive. For this reason it is important to find some new and cheaper alternatives to improve the meat fish color. Carotenoid concentration in rainbow trout depends on fish weigh, can reach 6-7 mg/kg in the flesh at specimens weighing 0.1-0.5 kg, and to 25 mg/kg at larger trout. It was noticed that improving the fish feed with a carotenoid concentration above 50 mg/kg dry matter does not induce a significant increase of meat fish pigmentation. It was not signaled that the carotenoid retention could be affected by feeding rate, water temperature or salinity. Some investigations on rainbow trout reported the positive role of adding carotenoids to diets on increasing their resistance against oxidative corruption stress. This review aims to present the effects of the addition of natural sources rich in carotenoids in the farmed trout feed. [ABSTRACT FROM AUTHOR]