This study examined the clinical use of routine administration of the Hopkins Competency Assessment Test on an inpatient geropsychiatry unit. The purpose was to determine whether the Hopkins Competency Assessment Test results influenced the psychiatrist's capacity assessment or confidence in that determination. The test was administered to all patients admitted voluntarily during an 18-week period. The attending psychiatrist determined treatment consent capacity and rated confidence in that determination, before and after review of the test results. Fifty seven patients were assessed. After review of the test results, the psychiatrist's capacity rating changed in only 2 (3.5%) cases. However, the test increased the psychiatrist's confidence ratings, particularly among the patients with cognitive impairment. The Hopkins Competency Assessment Test is not suited for routine administration among geropsychiatry inpatients. However, the test may serve a role as a supplementary tool for assessing treatment consent capacity among patients with evidence of cognitive impairment.