This study compares the efficacy of two drug regimens used for oral sedation in pediatric dental patients: chloral hydrate (50 mg/kg)/promethazine (1 mg/kg) and meperidine (1 mg/kg)/promethazine (1 mg/kg). Twenty-four pediatric dental patients, ASA Class I, were evaluated in this double-blind, randomized study. The patients ranged in age from 18 to 48 months. Each dental procedure under sedation was videotaped and rated independently by two raters. Intraoperative ratings of sleep, movement, crying, an overall behavior score for each treatment interval, and an overall behavior score for each sedation were also evaluated. No treatment was aborted for either regimen. In all cases, chloral hydrate/promethazine sedations had significantly better results for sleep (P = 0.0001), movement (P = 0.0168), crying (P = 0.0041), and overall behavior score (P = 0.0186) for the sedations compared to meperidine/promethazine sedations. Although chloral hydrate/promethazine sedations produced significantly better results, clinically, both drug regimens were equally effective.