Data supporting theoretical models linking autism spectrum disorders (ASD) to motor disturbance are inconclusive. In the present study, children and adolescents with ASD (n = 44) were compared with a matched group of typically developing individuals (n = 49) on both instrumental and observational assessments of motor abnormalities. No group differences were found in the instrumental data. However, more bradykinetic motor behavior was found using an observational scale in the ASD groups. More rigid motor behavior was found in the adolescents with ASD but not in the children. Individuals with ASD show significantly more hypokinetic behavior, which may not be strictly dopaminergic in origin, but may reflect a weak central coherency in neuronal networks related to the motor system in which developmental changes are present.