The purpose of this study was to evaluate the impact of granulocyte-colony stimulating factor (G-CSF) on the therapy for febrile neutropenia (FN). Our patient population differed significantly from those of previous studies as no patients received antimicrobial or CSF prophylaxis before randomization and all were solid tumor patients. When the diagnosis of FN was established, patients were started on intravenous meropenem 1 g every 8 hours and randomly assigned to receive G-CSF (5 mug/kg body weight per day subcutaneously) or not. Twenty-eight patients with 30 FN episodes received G-CSF and 25 patients with 30 FN episodes did not receive G-CSF according to randomization. The time to resolution of fever, recovery of neutrophil count over 1000/mm(3), duration of hospitalization, need for erythrocyte and platelet transfusion and mortality rate were similar in both study groups. Side effects of therapy were mild. These results provide preliminary evidence that G-CSF administration, in addition to effective antibiotic therapy as treatment of febrile neutropenic patients with solid tumor, does not help improve infection-related morbidity and mortality.