BACKGROUND: The current study compared 3 brief mental health screening measures in a sample of older patients in a primary care outpatient setting. Previous mental health screening research has been conducted primarily with younger patients, often with only 1 screening measure, thereby limiting the generalizability of findings. In addition, measures have not yet been compared in terms of their ability to discriminate between cases and noncases of psychiatric disorder. METHOD: One hundred thirty-four male patients attending their appointments at a primary care clinic in a Department of Veterans Affairs Medical Center participated in this study. Participants completed the General Health Questionnaire-12 (GHQ-12), the Symptom Checklist-10 (SCL-10), and the Primary Care Evaluation of Mental Disorders screening questionnaire and interview. RESULTS: Receiver operating characteristic analysis yielded the optimum cutoff scores on each brief mental health screening measure and showed that all 3 measures discriminated well between cases and noncases of psychiatric disorders. The 3 measures performed slightly better in terms of discriminating between cases and noncases of mood or anxiety disorders than between cases and noncases of any psychiatric disorder. There were no significant differences between the measures' abilities to accurately identify cases and noncases of disorder. CONCLUSION: Primary care physicians are encouraged to use brief mental health screening measures with their patients, since many report symptoms of psychological distress and disorder. It is recommended that the SCL-10 and GHQ-12 be used to detect mood or anxiety disorders in patients such as these because of the accuracy and brevity of these measures.