A brief 21-item symptom rating scale, the Psychiatric Outpatient Rating Scale (PORS), was developed for use in outpatient clinics. On the basis of its initial use with 86 patients, it was shown to have high internal and interjudge reliability and evidence of concurrent and construct validity. Scores on the PORS correlated significantly with the Global Assessment Scale and with the number of sessions of psychotherapy. For a subsample of 45 patients rated on the PORS at the beginning and termination of psychotherapy, seven symptoms revealed highly significant improvement. The PORS appears to be a potentially useful measure of change in outpatient clinics.