1. The correlation between plasma prolactin concentration and psychopathology, as assessed by the BPRS, was studied in 56 unmedicated schizophrenic patients (28 males, 28 females). 2. There was no significant correlation between plasma prolactin concentration and total BPRS score or each item score. 3. No significant correlation was found when the BPRS items were classified into five clusters, i.e., positive, excitement, cognitive, negative, and anxiety-depression symptoms. 4. When males and females were analyzed separately, no significant correlation was found except a weak negative correlation (rs = -0.388, p < 0.05) for hostility score in females. 5. The present study suggests that plasma prolactin concentration does not reflect psychopathology of schizophrenia.