A series of clinical-chemical tests was conducted in 68 schizophrenic out-patients under long-term neuroleptic medication, with particular consideration of the hepatic metabolism, i.e.: Erythrocyte sedimentation rate, alpha 1-glycoprotein, ceruloplasmin, fibrinogen, GPT, GOT, gamma-GT, total protein and serum-protein-electrophoresis. Furthermore, the glucose tolerance tests was carried out. In 44% of the patients an increased erythrocyte sedimentation rate and positive correlations with increased fibrinogen values were found. Increased gamma-GT-values were proven in 33% of the patients; they correlated positively with the increased GPT-and/or GOT-values as well as with pathological glucose tolerance values. Overweight of more than 10 kilos was found in 46% of the patients. A significant correlation between overweight and pathological glucose tolerance values existed. The results were interpreted as consequence of a light fatty liver.