Objective and Design: Psoriasis is a common, enigmatic, and recurrent disease. The precise etiology and pathogenesis of psoriasis are still unclear. Psoriasis has been treated as an inflammatory disorder related to an underlying Th1/Th17-dominated immune response. Interleukins are involved in the development of psoriasis lesions through Th-17-associated inflammation. Th1 and Th17 cytokines are found in skin lesions and in the peripheral blood of psoriasis patients. We sought to analyze serum levels of IL-1-beta, IL-8, IL-9, IL-27, IL-29, IL-35, IFN-gamma, TNF and TGF-beta in patients with psoriasis and healthy control volunteers. Material: Blood samples were collected from fifty-three patients with psoriasis and thirty-five healthy controls. Methods: Serum cytokines concentrations were determined using an enzyme-linked immunosorbent assay. Results: Serum IL-8, IL-9, IL-27, IL-29 and TNF levels were statistically significant in psoriasis patients. Detectable serum IL-9 levels were found in 47 patients of the 53 in the psoriasis group. Conclusions: Interleukins-8, 27, 29 and TNF levels measured in the serum of psoriasis patients were slightly elevated as compared to healthy controls in a weakly significant way. On the other hand, there were highly significant differences in IL-9 levels between the two groups.