Baseline stereotypic movements in 224 autistic children were studied as well as their relationship to certain demographic variables and measures of overall symptomatology and severity of illness. Prediction of haloperidol-related dyskinesias with measures of stereotypies and demographic variables was also attempted. Stereotypies were present in at least mild form in most children, with most showing moderate severity. Most stereotypies were in the orofacial area. I.Q. was found to be negatively related to stereotypies. Furthermore, across methods of assessment, severity and frequency of stereotypies were found to be positively related to overall symptomatology and severity of illness. No significant predictors of development of dyskinesias were found.