OBJECTS: It has been reported that the incidence of tardive dyskinesia(TD), the remarkable abnormal involuntary movement, was higher in the schizophrenics with high blood sugar levels and that TD had been improved by small amount of insulin-injection for 90 days. And also it was generally known that the blood lipids were higher in the schizophrenics with tardive dyskinesia. Thus, we tried to replicate the correlations of abnormal involuntary movements with blood sugar levels and blood lipids in chronic schizophrenics treated with antipsychotics. METHODS: Thirty-eight male schizophrenic inpatients who were stable in clinical state with medications, were included. The patients who had been already diagnosed as diabetes mellitus(DM), organic brain disorder, substance-related disorder, physical illness were excluded and also we excluded female patients to remove the hormonal effect on TD. Eleven patients who ranked higher(above five) in the Abnormal Involuntary Movement Scale(AIMS) were assigned into 2 groups, a dibenese group and a placebo group. Diabinese or placebos were administrated for 3 weeks with antipsychotics and AIMS was rechecked. RESULTS: There were no correlations between the total AIMS scores and blood sugar and lipids levels in all subjects. The means of total and subscale scores(objective, face, and extremity) of AIMS did not reveal statistical significances between diabinese and placebo groups. However(total, jaw, face, upper arm, and objective feeling), were statistically higher in the diabinese group than those in the placebo group. And correlations of total cholesterol(TC) with fast blood sugar(FBS), weight with body mass index(BMI) and waist, total glycerol (TG) with BMI were statistically significant. CONCLUSION: In this study, there were statistical significances in the changes in ratings of AIMS scores between the diabinese group and the placebo group. Application of oral hypoglycemic agent might be a way of improving abnormal involuntary movements in schizophrenics with abnormal involuntary movements or TD. Althogugh it was not certain that there were correlations of abnormal involuntary movement with blood sugar and lipids, correlations of TC/TG with AIMS, of FBS with AIMS cautiously suggest that the regular check of HbA1C, waist, and weight are recommended for schizophrenics.