A series of 160 consecutive patients undergoing tonsil and adenoid surgery for upper airway obstruction is reported. The ages ranged from 8 months to 13 years. Sixty-seven percent were 2, 3, or 4 years of age. All were routinely admitted overnight postoperatively. Forty-five (28%) remained in the hospital longer than one night (2 to 20 days). Postoperative respiratory problems were the reason for prolonged hospital stay in 30 of these 45 patients. Preoperative “danger-signals” of potential postoperative respiratory problems were: a history of severe obstructive symptoms with apnea and moderate or strongly positive sleep study, daytime somnolence, need for urgent T&A, and cardiomegaly. Risk factors present in a smaller number of patients were obesity, congenital stenosis of airways, and bronchopulmonary dysplasia. We suggest that children with these danger signals not be considered as candidates for outpatient T&A surgery.