The aim of this study was to evaluate the efficacy and safety of piperacillin/tazobactam (PIP/TAZO) and cefozopran (CZOP) monotherapy in pediatric cancer patients with febrile neutropenia (FN). A total of 119 febrile episodes in 49 neutropenic pediatric cancer patients (20 females and 29 males) with a median age of 6.8 years (range, 0.3-18.4 years) received randomized treatment either with PIP/TAZO 125 mg/kg every 8 hr or CZOP 25 mg/kg every 6 hr. Clinical response was determined at completion of therapy. Durations of fever and neutropenia, the need for modification of the therapy, and mortality rates were compared between the two groups. The frequency of success without modification of treatment was not significantly different between PIP/TAZO (59.6%) and CZOP (53.2%). Durations of fever and antibiotic therapy did not differ between the treatment groups, and no major side effects were observed in either group. PIP/TAZO and CZOP monotherapy were both effective and safe for the initial empirical treatment of pediatric cancer patients with FN.