BACKGROUND: This review of children and adolescents with nonorbital soft-tissue sarcoma of the head and neck was undertaken to describe late sequelae of treatment, as manifested primarily by problems with statural growth, facial and nuchal symmetry, dentition, vision and hearing, and school performance. PROCEDURE: Four hundred sixty-nine patients entered the IRS-II and -III protocols with localized, nonorbital soft-tissue sarcomas of the head and neck from 1978 through 1987. Their overall survival rate was 53% (250/469) at 5 years. Two hundred thirteen patients were surviving relapse-free 5 or more years after diagnosis, for whom there were serial height measurements at 2 or more years after initiation of therapy. Their median age at diagnosis was 5 years; the median length of follow-up was 7 years. All received multiple-agent chemotherapy, and all but 3 received irradiation to the primary tumor volume. Sixty-eight percent of the tumors arose in cranial parameningeal sites, 22% in nonparameningeal sites, and 10% in the neck. We reviewed flow sheets submitted to the IRS Group Statistical Office to ascertain which late sequelae were recorded. RESULTS: One hundred sixty-four patients (77%) had one or more problems recorded. One hundred ninety of the two hundred thirteen patients (89%) were under 15 years of age at study entry, and at follow-up 92 (48%) had failed to maintain their initial height velocity, which had decreased by more than 25 percentile points from the original value. Thirty-six of the one hundred ninety patients (19%) were receiving growth hormone injections. Hypoplasia or asymmetry of tissues in the primary tumor site was reported in 74 patients, and 13 underwent reconstructive surgery. Poor dentition or malformed teeth were noted in 61 patients. Impaired vision developed in 37 patients, owing primarily to cataracts, corneal changes, and optic atrophy. Thirty-six patients had decreased hearing acuity, and 9 were fitted with hearing aids; 5 of these 9 had received cisplatin. Thirty-five patients were noted to have problems learning in school. Four patients developed a second malignancy (two sarcomas, one carcinoma, one leukemia). CONCLUSIONS: Late sequelae affected the majority of these patients treated for soft-tissue sarcoma of the head and neck on IRS-II and -III. The potential impact of certain sequelae could be reduced by specific measures, such as surgical reconstruction and hormonal therapy. Late sequelae must be taken into account in designing future curative treatments.