Our aim was to characterize effectiveness and complications in children receiving oral midazolam alone, nasal midazolam alone, or oral midazolam with other sedatives. Children received oral midazolam alone, nasal midazolam, or oral midazolam in combination with other sedative medications. All subjects received a presedation history and physical examination and were sedated per protocol by any of 28 resident providers under attending supervision. Sedations were rated for success and complications by clinicians. Postoperative complications were assessed by trained staff up to 48 hours postoperatively. Seven hundred and one encounters, completed over 24 months, yielded 650 usable sedations. The majority of children were healthy (469; 68.2%) and 86% (532) weighed between 10 and 25 kg. Sedations were deemed successful in about 80% of cases. Planned treatment was completed in over 85% of encounters. Oral midazolam alone yielded the best behavior. Physical assessment factors of behavior and age were correlated (P = .035) with effectiveness. Hiccups and a positive medical history were significantly related (P = .049). Side effects of either nausea/vomiting, dysphoria, or hiccups occurred in less than 10% of cases. All 3 regimens were effective with minimal postoperative complications.