The effectiveness of empiric therapy was evaluated in 186 cancer patients who experienced 417 febrile and neutropenic episodes during the last 4 years. Ninety-eight patients experiencing 244 episodes were treated with empiric antibiotic therapy with mezlocillin and tobramycin. The response mte to the empiric treatment was 88% for bacterial infections and 58% for unexplained fever. Fluconazole 200 mg IV daily was added to the empiric antibiotic therapy in the subsequent 173 episodes experienced by 90 patients, of whom 12 had also been evaluated in the previous group. The addition of fluconazole improved the response rates to 90% in bacterial infections and to 86% in unexplained fever. In proven fungal infections in neutropenic patients, empiric antibiotic therapy combined with higher doses of fluconazole seemed beneficial. This study suggests that fluconazole 200 mg IV daily is an effective adjunct to empiric antibiotic therapy, but higher doses of fluconazole are preferable in proven fungal infections.