UNLABELLED: Autism is a pervasive neurodevelopmental disorder. Because of the deficits associated with the condition, sedation of children with autism has been considered more challenging than sedation of other children. OBJECTIVE: To test this hypothesis, we compared children with autism against clinical controls to determine differences in requirements for moderate sedation for MRI. MATERIALS AND METHODS: Children ages 18-36 months with autism (group 1, n = 41) and children with no autistic behavior (group 2, n = 42) were sedated with a combination of pentobarbital and fentanyl per sedation service protocol. The sedation nurse was consistent for all patients, and all were sedated to achieve a Modified Ramsay Score of 4. Demographics and doses of sedatives were recorded and compared. RESULTS: There were no sedation failures in either group. Children in group 1 (autism) were significantly older than group 2 (32.02+/-3.6 months vs 28.16+/-6.7 months) and weighed significantly more (14.87+/-2.1 kg vs 13.42+/-2.2 kg). When compared on a per-kilogram basis, however, group 1 had a significantly lower fentanyl requirement than group 2 (1.25+/-0.55 mcg/kg vs 1.57+/-0.81 mcg/kg), but no significant difference was found in pentobarbital dosing between groups 1 and 2, respectively (4.92+/-0.92 mg/kg vs 5.21+/-1.6 mg/kg). CONCLUSION: Autistic children in this age range are not more difficult to sedate and do not require higher doses of sedative agents for noninvasive imaging studies.