The development of pulmonary side effects, especially pulmonary fibrosis, during treatment with bleomycin is well documented in adult oncology patients, but not in children. A report of fatal pulmonary fibrosis which developed after exposure to oxygen while under anesthesia in a 3-year-old boy treated with bleomycin exemplifies the problem. The prevention of long-term complications associated with bleomycin is especially important in children, since a child cured of a malignant neoplasm may enjoy many years of productive life. Given the present limitations, guidelines for management of pediatric patients given bleomycin include: 1) discontinuation of bleomycin therapy with the onset of symptoms; 2) serial pulmonary function testing during the course of treatment; and 3) early treatment with high-dose cortico-steroids (prednisone 2 mg/kg/day) if symptoms occur.