The purpose of this paper is to present a new scale—the RP scale—for use in the quantification of mental status data from psychotic patients. Many similar scales are available, such as the Lorr et al Multidimensional Scale for Rating Psychiatric Patients (MSRPP), the Goodrich Quantification of Psychotic Symptom Severity (QPSS), the Malamud and Sands Psychiatric Rating Scale, and others.1-7 However, none of those examined satisfactorily met all the requirements of the multidisciplinary studies in which the authors were engaged. We therefore attempted to construct a scale that (a) could be used repeatedly by psychiatrists after brief (30-60 minute) interviews, (b) provided a quantified profile which was an accurate reflection of clinical judgment and impressions, (c) was so arranged that it could be easily processed by computors, and correlated with data from other disciplines (psychology, biochemistry, neurophysiology), and (d) focused on the degree and nature