Concern over the rising cost of health care has created a trend toward outpatient surgery. Because adenotonsillectomy is such a frequently performed procedure, there is pressure on many otolaryngologists to do this operation on an ambulatory basis. A prospective study was undertaken to evaluate the incidence and severity of postoperative hemorrhage, protracted emesis, and fever at specified times within the first 24 hours after surgery. Over a 1-year period, 1000 tonsillectomy and/or adenoidectomy patients were studied. There was a 2.1% incidence of serious complications within the first 6 postoperative hours. The incidence of serious hemorrhage, fever, and protracted emesis was 0.7% each. The incidence of significant complications between the 6th and 24th postoperative hours was 1.7%. Hemorrhage occurred in 0.4% of the patients, fever in 0.7%, and protracted emesis in 0.6%. The total incidence of hemorrhage during this time period was 1.1%. There were no deaths. The greatest percentage of complications occurred within the first 6 postoperative hours. Based on this study, outpatient tonsil and adenoid surgery should be followed by at least 6 hours of postoperative observation before discharge. The choice to perform ambulatory tonsil and adenoid surgery depends on the professional judgment of the operating physician based on this and other recent studies, the sophistication of the physician's ambulatory surgery center, and the medical and social background of the patient.