Secondary malignancies are a well-known late complication occurring in patients who undergo bone marrow transplant (BMT) during childhood. A boy with acute lymphoblastic leukemia experienced a BM relapse at the age of 14 years and underwent an autologous BMT conditioned with TBI and melphalan. Sixteen years later a malignant mesothelioma of the peritoneum was diagnosed. A surgical approach according to the Sugarbaker technique and hyperthermic peritoneal perfusion with CDDP and Adriamycin were performed. The patient is alive and well after a follow-up of 20 months. To the authors' knowledge this is the first case of mesothelioma as a secondary malignancy after BMT.