Case records of the 157 children with soft tissue sarcoma in the Manchester Children's Tumour Registry diagnosed between 1954 and 1983 were reviewed for reference to diagnostic features of neurofibromatosis (NF). Interviews were carried out with 124 families of these children. Four children in the series were identified as having NF. All four were boys, very young at diagnosis, and had rhabdomyosarcomas of the bladder or prostate. In addition, there were indications that a further nine children may have been affected. It is suggested that NF may be more common in children with soft tissue sarcoma than previously thought and that clinicians should be alert for signs and symptoms of NF in such children and their families. Affected children may be at increased risk of developing further malignancies.