Liposomal daunorubicin (DaunoXome = DNX) has been used in 14 children with recurrent or progressive growing brain tumor. DNX was given as a 1-h intravenous infusion with a dose of 60 mg/m2, once every 4 weeks, up to a cumulative dose of 600 mg/m2. At 3-month intervals the tumor process was evaluated on MRI or CT scan. Tumor response and toxicity of DNX were recorded according to the WHO guidelines. In 6 of the children a response has been established: 2 had complete responses, of which one relapsed again after 3 months; in 3 children a partial response was found. Two children showed stable disease. In 6 children the tumors grew progressively. In all responding children a remarkable subjective response was found. The toxicity of DNX at this dose was mild with a mild bone marrow depression and a slight but certain cardiotoxicity in 3 children. For the whole group the left ventricular function decreased with 13.8%. In 1 child the DNX treatment was stopped because of a decrease of the shortening fraction to 20%. In 4 children some hair loss was observed at the end of the treatment. In 3 children mental depression occurred that was associated with the administration of DNX. DNX is a well-tolerated and effective drug in the treatment of slowly progressive or recurrent brain tumors in children.