Psoriasis is an immune mediated chronic inflammatory disease of unknown etiology and characterized by epidermal hyperplasia and inappropriate immune activation, which affects the skin and joints as well.The immunopathogenesis of psoriasis involves changes in the innate and acquired (T lymphocytes) immune system. The cells of the innate immune system when activated produce growth factors, cytokines, and chemokines that act on cells of the acquired immune system and vice versa, being characterized as atype 1 immune response disease. Fish oil n-3 polyunsaturated fatty acids, mainly eicosapentaenoic (EPA), and docosahexaenoic acids (DHA), reduce symptoms in many inflammatory skin diseases. The mechanism of action of fish oil in the treatment of psoriasis is widely based on the alteration of epidermal and blood cell membrane lipid composition. In the present study, we performed a review of the several studies, which analyzed the action of n-3 polyunsaturated fatty acids in patients with psoriasis. Taken together, the majority of the studies showed that n-3 polyunsaturated fatty acids, mainly from marine origin, have beneficial effects and can be utilized as adjuvant therapy in psoriasis treatment. Both oral and intravenous administration of fish oil n-3 polyunsaturated fatty acids had positive effects. However, further studies are warranted to answer many intriguing questions, for instance, the ideal quantity of fish oil to be utilized, the effect on different forms and severity of psoriasis and last, but not least, the consequences of using fish oil n-3 polyunsaturated fatty acids on the cardiovascular features of patients with psoriasis.