Tonsillectomy and adenoidectomy in patients with Down syndrome usually relieves symptoms of upper airway obstruction due to adenotonsillar hypertrophy. A retrospective review of 16 patients with Down syndrome who underwent a tonsillectomy and adenoidectomy was conducted to define early postoperative morbidity, and to evaluate the results of the procedure. Fifteen of 16 patients had upper airway obstruction manifest by adenotonsillar hypertrophy. One had adenoid hypertrophy only. Tonsillectomy and adenoidectomy (13), adenoidectomy (1), tonsillectomy (1), and UP3/adenoidectomy (1) were performed on these patients. Four patients (25%) required observation in an intensive care setting the first night. An average hospital stay of 2.1 days was noted with a range of 0 to 7 days. Significant postoperative apnea was common, and oxygen was used in over 60% of patients. Symptoms were resolved in 69% of patients at last follow up. In conclusion, tonsillectomy and adenoidectomy can be a useful procedure for children with Down syndrome and obstructive sleep apnea, however overnight hospitalization for observation and treatment of persistent apnea is appropriate.