We evaluated the efficacy and safety of piperacillin-pefloxacin potentially associated to vancomycin as a non nephrotoxic antimicrobial therapy in febrile neutropenic cancer patients, treated with nephrotoxic chemotherapy. Fifty-seven patients: 49 with solid tumors and 8 non-Hodgkin lymphomas, were treated during 85 episodes with: piperacillin 4 g IV every 8 h pefloxacin 400 mg IV every 12 h. If the patient remained febrile after 72 h, 1 g of vancomycin IV was added every 12 h. The mean duration of neutropenia was 7 days (3-14 days). In 44 episodes, the granulocyte nadir was < 100/mm3. Infection was microbiologically documented in 17 episodes (20%) with ten Gram-positive cocci and 11 Gram-negative bacilli. There were 64 apyrexia with piperacillin-pefloxacin (75%) and further 14 were resolved by the addition of vancomycin (total success = 92%); three early changes because of clinical deterioration (two episodes) or germ resistance (one episode); three protocol violations, and one apyrexia by addition of amphotericin. Neither septic death nor toxicity were observed. We conclude that this empirical treatment is active and safe and avoids nephrotoxicity in cancer patients heavily treated with nephrotoxic chemotherapy.