Introduction: The use of a permanent Central Venous Catheter (CL) in oncologic patients allows a secure and rapid access. Infection is an important risk. "Lock therapy" (LT) consists of the application of a high concentration of antibiotics in the lumen of the catheter, for the purpose of eradicating bacteria. Objective: To describe the use of LT associated with the systemic use of antibiotics in CL infections occurring among pediatric oncological patients. Methods: A descriptive, restrospective review of charts of children seen at the Oncology Unit, Roberto del Rio Children's Hospital, 2005 to 2007. Evaluated parameters included culture and sentitivity studies, removal of CL and mortality. Results: There were 11 episodes of infection associated to CL in 8 patients, most frequently associated to Staphylococcus coagulase-negative. The CL was preserved in 7 patients. There was no mortality associated to infection. Conclusion: For this group, LT and systemic antibiotics preserved the CL in most patients. Randomized prospective studies are needed in a larger population to support these findings.