Organ allograft recipients are at higher risk for malignancies development. This risk is known to be different in different types of tumours. Skin cancers and lymphoproliferative disorders have been described to be ones the most frequent (comprising 15-25% of all malignancies). Here, we present the case of expansive formation localized near the renal allograft in patient, whose native kidneys failed as a consequence of long-term cyclosporine A therapy after orthotopic heart transplantation. The maintenance immunosuppression consisted of combination of cyclosporine A, mycophenolate mofetil and steroids. The expansion offside of transplanted kidney was detected by routine ultrasound examination. After indifferent neurological symptoms, sepsis, and then multiorgan failure occured. Shortly after acute surgery patient died. Autopsy and histopathology showed lymphoproliferative disorder--mo- nomorphic type of posttransplant lymphoproliferative disorder (PTLD). Occurence of PTLD in organ transplantation is discussed.