A need exists for a safe and effective oral preanesthetic medication for use in children undergoing elective surgical procedures. We evaluated the effectiveness of three different doses of oral midazolam when administered in combination with atropine prior to ambulatory surgery. In this randomized, double-blind, placebo-controlled study, 124 children, ages 1-10 yr, received midazolam, 0.25, 0.50, or 0.75 mg.kg-1 po, and atropine, 0.03 mg.kg-1 po, mixed with apple juice, or a placebo (containing the midazolam vehicle, atropine, and apple juice). A blinded observer noted the child's level of sedation, the quality of separation from parents, and the degree of cooperation with an inhalation induction of anesthesia. Picture-recall was used to assess the amnesic effect of midazolam in children over 5 yr of age. Midazolam 0.75 mg.kg-1 produced significant sedation at 30 min. After procedures lasting an average of 106-113 min, recovery was not prolonged by the oral midazolam-atropine combination. We concluded that oral midazolam 0.5-0.75 mg.kg-1 is an effective preanesthetic medication for pediatric outpatients.