Objective: There are limited data focusing on incidence and manifestations of cytomegalovirus (CMV) inchildren with acute lymphoblastic leukemia (ALL) apart from bone marrow transplant recipients. In thisstudy, we aimed to review our experience regarding the manifestations, treatment, and outcome of cytomegalovirus infection in pediatric ALL patients.Methods: We retrospectively reviewed the clinical characteristics of patients with ALL that were diagnosed with CMV disease while they were on standard chemotherapy.Results: Fourteen patients were included in the std. Fever was the most common symptom (64%). Eyes,lungs and liver were the most commonly involved organs in CMV disease. Lymphopenia was found in mostof the patients. At the time of diagnosis, 50% of the patients were on maintenance phase of chemotherapy. All patients were treated with intravenous ganciclovir. Two patients died because of concomitantinfections, and two children with retinitis had permanent visual sequelae while others had a completerecovery.Conclusion: In children with ALL, CMV is an important pathogen with serious consequences includingretinitis which may be asymptomatic and result in complete visual loss. Not only during intense chemotherapy but also in maintenance phase CMV disease may occur. Especially when prolonged (>7 days) febrile neutropenia and lymphopenia is present, CMV must be kept in mind in the differential diagnosis.