Twenty patients with soft-tissue sarcomas arising within previously irradiated fields have been analysed. The initial radiation dose ranged from 8.8 to 70 Gy, comprising either orthovoltage or megavoltage treatment. The latent interval following radiotherapy ranged from 7 to 45 years (mean 16.8 years). The commonest histological subtype was malignant fibrous histiocytoma. Four patients required forequarter amputation. The 5-year survival was only 14 per cent. The high morbidity and mortality accompanying post-radiation sarcomas must be borne in mind when the choice between therapeutic options for potentially curable cancers is finely balanced.