Cisplatin (CDDP) is known to induce nephrotoxicity. In this retrospective study, we have investigated the evolution of plasma creatinine in long term therapy with CDDP. We have studied case history, mode of administration of CDDP and associations with other chemotherapeutic agents or drugs which could potientiate CDDP renal damage (non steroidal anti-inflammatory agents, analgesics, antibiotics, antihypertensive agents, diuretics and contrast media). Mean creatinine concentration versus time rises significantly. This elevation is significantly higher in patients with hypertension, diabete, one functional kidney, or abdominoperineal irradiation. The association with other drugs has not proved a real influence on creatinine evolution.