Growth patterns were surveyed in 303 children with acute lymphoblastic leukemia who had remained in continuous first complete remission for a minimum of 1 year (median 3 years). Chemotherapy was given for 3 years, and central nervous system prophylaxis consisted of cranial irradiation at a total dose of 18 Gy or intravenous high-dose methotrexate (1.5-6 g/m2 for three to six doses). Intensive chemotherapy, including cyclophosphamide, doxorubicin, and cytosine arabinoside was given to children with high-risk features. Two of 205 children with low- or intermediate-risk features and 13 of 98 children with high-risk features showed a decrease in the growth rate of less than -2 SD. In 14 of these 15 patients, the age at onset was over 9 years and growth failure became most predominant in the prepubertal period: ten of these children showed a tendency toward delayed pubertal development, but eight showed later catch-up growth with pubertal maturation after completion of chemotherapy. Thus, chemotherapy appeared to contribute temporarily to the growth failure and gonadal impairment that occurred in the prepubertal period. No obvious correlation between the administered cranial irradiation and growth failure was found, but further study with a longer follow-up will be necessary to determine the long-term effects of irradiation on subsequent growth patterns in children.