Obstructive sleep apnea syndrome was studied in 32 children, aged 2 to 14 years, in the sleep-wake disorders center at Montefiore Hospital and Medical Center during the years 1977 to 1980. All children under-went all-night polysomnograms; 17 of these children had surgery to relieve airway obstruction and seven had a repeat polysomnographic study 4 to 6 weeks following the surgery. There was a significant improvement in the number of obstructive apneas and in other apnea indices following surgery. There was no significant effect on the durations and the proportions of the various sleep stages, on sleep efficiency, or on the number of awakenings.