Extrapyramidal side effects of neuroleptics are important in clinical practice. Study of extra-pyramidal side effects is also of importance for researchers who test new antipsychotic agents or study tardive dyskinesia. A french translation of the Simpson-Angus Rating Scale of extra-pyramidal side effects thus appeared useful. This scale contains 10 items: Gait, Arm dropping, Shoulder shaking. Elbow rigidity, Wrist rigidity, Leg pendulousness, Head dropping, Glabella Tap, Tremor, Salivation. Each item is rated between 0 and 4. A total score is obtained by adding the items and dividing by 10. Scores of up to 0.3 are considered within the normal range. The scale original has been validated in a population of fourteen psychotic inpatients taking, in a double-blind procedure, placebo, haloperidol 6 mg/day or haloperidol 30 mg/day. Patients receiving haloperidol 30 mg/day presented more extrapyramidal symptoms than patients under placebo. The Simpson Angus rating scale has also been shown to have clinical validity and high inter-rater reliability. It can be routinely used in clinical drug evaluation. The french version was used in a population of 30 psychotic inpatients fulfilling the DSM III-R criteria of schizophrenic disorder. Patients were treated for at least two weeks, orally, either with a phenothiazine (chlorpromazine 350 mg) or a butyrophenone (haloperidol 15 mg). 10 of the 30 patients received, in addition, anticholinergic agents (trihexiphenidyl, 5 mg). The french version of The Simpson Angus Rating Scale appeared to be easy to use and not time-consuming. Interraters correlation was high. Patients receiving butyrophenones or phenothiazines had no significantly different ages and sociodemographic characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)