The development of sarcomas in three generations of a family with neurofibromatosis (NF) is described. A 7-month-old boy developed a prostatic rhabdomyosarcoma. Family history revealed that his maternal grandmother had died of a malignant peripheral nerve sheath tumor at age 37 years and had been affected with neurofibromatosis. His mother (aged 36 years) has also developed a malignant peripheral nerve sheath tumor and NF has been confirmed in both mother and son. This family illustrates a cluster of sarcomas associated with NF and shows the importance of thorough investigation of reported family illnesses.