Motor skills were assessed in 397 toddlers, and it was demonstrated that atypically developing toddlers exhibited significantly greater motor skill abilities than toddlers with autistic disorder. No significant difference on gross or fine motor skill abilities were found between atypically developing toddlers and toddlers with pervasive developmental disorder-not otherwise specified (PDD-NOS), or between toddlers with autistic disorder and toddlers with PDD-NOS. Gross and fine motor skills were found to be more impaired for toddlers with autistic disorder compared to the atypical development group. Furthermore, differences in gross or fine motor skills between the autistic disorder and the PDD-NOS group approached significance. Approximate effect sizes were also calculated. Implications of the results are also discussed. (Contains 4 tables.)