Prolonged immunosuppressive therapy used in transplantation is complicated by malignancies. Kaposi’s sarcoma (KS) is one of the most common post transplant malignancies. A variety of factors appear to contribute to the development of KS including: genetic factors, sex hormones, Immunosuppression and oncogenic viruses. We describe three cases of kidney transplant recipients who developed KS concurrently or shortly after cytomegalovirus (CMV) infection in the first year after transplantation. Case 1: A 50 years old man received a renal allograft. He was prescribed a triple immunosuppressive regimen. At the third month the patient had CMV disease. He presented at the forth month with KS in an aggressive manner involving oropharyngolaringeal mucosa, gastrointestinal tract and diffuse skin lesions. Despite stop immunosuppressive therapy KS didn’t regress and chemotherapy started. Case 2: A 53 years old man at the fifth month of renal transplant turned to hospital with purple skin lesions and constitutional complaints. Kaposi’s sarcoma and CMV infection confirmed. Antiviral therapy started and immunosuppressive drugs reduced, the patients had remission. Case 3. A 43 years old women renal transplant recipient at 8th month of transplantation presented with weakness, fatigue, thrombocytopenia, anemia and purpuric lesions. CMV infection confirmed and gancyclovir started after one month she presented with purple lesions on the legs. KS confirmed and radiotherapy started. Although many factors involved in KS in these 3 patients occurrence of KS concurrently or shortly after CMV infection, and early appearance of KS. (Before 1 year) after transplantation suggest it is involved in inducing