The frequency and clinical characteristics of plasmodium infection were reported in 420 renal transplant recipients who were followed in the Transplantation Unit and Out-Patient Clinic of the Medical School of Istanbul. Plasmodium infection was diagnosed in eleven (9 male, 2 female) of the 420 patients (2.6%). Ten of the patients were transplanted in India, and one in our institution. The mean duration between the transplantation and the diagnosis of malaria was 21.7 + 44.4 days in patients who were transplanted in India. All of the patients were taking triple immunosuppressive drugs (CsA, AZA, PRED). Plasmodium falciparum was diagnosed in 6 patients, P vivax in 1 patient and P malariae in 1 patient. Also mixed infection with P falciparum and P malariae was diagnosed in 3 patients. After definite diagnosis, the patients were hospitalized. Chloroquine phosphate plus primaquine phosphate was administered for P vivax infection, whereas chloroquine phosphate alone was given for P falciparum and P malariae infection as a first line antimalarial therapy. As a result of therapy, infection improved clinically and the plasmodia disappeared rapidly from the thick blood film in 10 of the patients. Severe hemolysis and acute renal failure developed in one patient, who improved after hemodialysis therapy and exchange transfusions. It was concluded that malaria is quite a frequent infection of transplant recipients who get their allografts from donors living in high-risk areas, and all transplant recipients having this kind of transplantations should be suspected and examined for malaria. This may help to diagnose and treat the complication in the early period, thus resulting in an improved prognosis for this potentially life-threatening complication of the posttransplant period.