Fifty-four rhabdomyosarcomas in children affected mainly the pelvis and scrotum, 22 cases, head and neck, 19, and limbs and limb girdles, 11. Rhabdomyosarcomas of the female genital tract occurred only in children under 2 years, and those in the lower eyelid presented in the first year of life. A leiomyosarcoma-like appearance, and an undifferentiated small cell sarcoma sometimes mimicking Ewing's tumour, were patterns giving rise to diagnostic difficulty. Many fine gradations from undifferentiated embryonal to almost purely differentiated "pleomorphic" examples, made microscopic classification arbitrary. However, the histological pattern had no bearing on prognosis in children in this series. Of the 46 cases adequately followed, 43 are dead. Two of the 3 long-term survivors had paratesticular tumours.