Introduction: Behcet's disease (BD) is a chronic systemic disorder characterised by oral and genital ulcerative lesions, ocular and cutaneous manifestations. Cytokines are the major mediators of immunologic and inflammatory reactions. Nitric oxide is reactive nitrogen intermediate which plays a key role in pathogenesis of many inflammatory and autoimmune skin diseases. The study was conducted to determine serum interleukin-2 (IL-2), interleukin-6 (IL-6), tumour necrosis factor (TNF)-alpha and nitric oxide levels in relation to the pathogenesis of Behcet's disease. Materials and Methods: Serum IL-2, IL-6, and TNF-alpha levels were measured with test kits by enzyme-linked immunosorbent assay (ELISA) method, while serum nitric oxide levels were determined with a test kit by colorimetric method. Serum IL-2, IL-6, TNF-alpha and nitric oxide concentrations in 27 patients with Behcet's disease and in 16 healthy controls were determined by extrapolation from their standard curves. The significance of the mean differences between the 2 groups was assessed by the Mann-Whitney U test. Results: The serum levels of IL-2, IL-6, TNF-alpha, and nitric oxide concentrations in patients with BD were significantly higher than those of the controls (P < 0.001). Conclusion: Our results suggest that elevated levels of IL-2, IL-6, TNF-alpha, and nitric oxide in Behcet's disease appear to be related to the disease.