Background. The empirical use of antibiotic treatments is widely accepted as a means to treat cancer patients in chemotherapy who have fever and neutropenia. Intravenous monotherapy, with broad spectrum antibiotics, of patients with a high risk of complications is a possible alternative. Methods. We conducted a prospective open-label, randomized study of patients with lymphoma or leukemia who had fever and neutropenia during chemotherapy. Patients received either monotherapy with ticarcillin/clavulanic acid (T) or ceftriaxone plus amikacin (C+A). Results. Seventy patients who presented 136 episodes were evaluated, 68 in each arm of the study. The mean neutrophil counts at admission were 217cells/mm 3 (T) and 201cells/mm 3 (C+A). The mean duration of neutropenia was 8.7 days (T) and 7.6 days (C+A). Treatment was successful without the need for modifications in 71% of the episodes in the T group and 81% in the C+A group (p=0.23). Treatment was considered to have failed because of death in two episodes (3%) in the T group and three episodes (4%) in the C+A group, and because of a change in the drug applied in one episode in the T group and two episodes in the C+A group. Overall success was 96% (T) and 93% (C+A). Adverse events that occurred in group T were not related to the drugs used in this study. Conclusion. In pediatric and adolescent patients with leukemia or lymphoma, who presented with fever and neutropenia, during chemotherapy, ticarcillin/clavulanic acid was as successful as the combination of ceftriaxone plus amikacin. It should be considered an appropriate option for this group of patients at high risk for infections.