It is considered several cytokines are effective in pathogenesis and theraphy of diabetes mellitus. The aim of this study was to investigate serum concentrations of interleukin-1 beta, interleukin-2, interleukin-6 and interleukin-10 cytokines thought to have relationship with diabetes mellitus and serum retinol, alpha-tocopherol and vitamin D-3 levels notified they have constructive effects on diabetes in streptozotocyne induced diabetic rats. Male Wistar-Albino rats between 7-8 weeks old and weighing 180-210 g were used. Streptozotocin induced and blood glucose levels were found between 230-390 mg dL(-1) diabetic 25 rats formed the study group and 15 healthy rats constituted the control group. Serum cytokine levels in both groups were evaluated by solid phase sandwich ELISA method and serum vitamin levels were established by HPLC. Serum interleukin-1 beta, interleukin-6 and interleukin-10 levels were not sufficient to constitute a statistical importance between groups. However, in diabetic group decreased interleukin-2 levels (p <= 0.05) were established. Besides, decreased retinol and vitamin D, levels (p <= 0.05) were detected in diabetic group but reduction in levels of alpha-tocopherol did not reach statistical significance. In conclusion, decreased serum interleukin-2 levels established in diseased group may indicate this cytokine has a part in the pathogenesis of diabetes mellitus and reduced vitamin levels may exhibit they used for disposal of free oxygen radicals. Besides, increased vitamin D-3 consumption may be due to its disposal in T cell regulation.