Cyclosporin A is a compound widely used as an immunosuppressive drug, particularly, in case of kidney transplantation to prevent rejection of transplanted organ. This study aimed to investigate the bad side effect of acute and chronic treatment with cyclosporin A on liver and kidneys by measuring liver enzymes and kidney function tests in serum. Male rats were used as experimental model in this study. The results of this study concluded that, chronic treatment with cycloosprin A leads to increase in serum urea, creatinine, and uric acid significantly compared to control, also, ALT and Alkaline phosphatase activities in serum were increased by chronic administration of cyclosporine A for four weeks. Decrease of serum albumin and total protein were observed significantly compared to control groups.