BACKGROUND The incidence of malignancies after transplantation is higher when compared with expected cancer in control patients, particularly skin and female genital cancer, non-Hodgkin's disease and Kaposi's sarcoma. The aim of this study is to evaluate the frequency and the efficacy of the treatment of cancer following renal transplantation. METHODS A retrospective analysis of 404 recipients was performed and it showed the onset of 15 cancers (8 skin cancers, 3 Kaposi's sarcomas, 2 renal carcinomas, 1 urotelioma and 1 colon cancer) in 11 patients (3.7%). At the time of diagnosis, the mean period of immunosuppressive therapy (7 cases of double therapy, 4 cases of triple therapy) was 44.8 months. Skin cancer (53.3%) and Kaposi's sarcoma (20%) were the most frequent in personal experience as reported in literature. Neither lymphomas, nor female genital cancers were detected. RESULTS All the cases were surgically treated, except patients with Kaposi's sarcoma, whose immunosuppressive therapy was reduced without alteration of renal function. Death-rate was 0.25% (1 case), the remaining patients show no signs of local recurrence or metastasis with preserved renal function except for the patient with renal carcinoma of the transplanted kidney, who underwent nephrectomy and returned in replacement therapy. CONCLUSIONS The conclusion is drawn that the research of relationship between type of immunosuppressive therapy and cancer incidence and careful clinical and instrumental examination of transplant patients may contribute to reduce the onset of neoplastic degenerations and lead to an early diagnosis.