The prognostic validity of the Rorschach Rating Scale was assessed with schizophrenic patients. Through the use of a standardized standardized structured interview and a diagnostic system for schizophrenia based on the use of discriminant function analysis with nonpathognomonic symptom combinations, a reliable an valid system was used to establish the criterion diagnosis. Outcome criteria used included a variety of measures of schizophrenic thought disorder. The results help to establish the practical utility of the PRS empirically with schizophrenic patients by demonstrating efficient prediction when other relevant demographic and nontest variables have been controlled. Furthermore, the concept of ego strength from which the PRS was developed does not appear to be too global a characteristic when the area for change is specifically delineated.