Depression, a common and treatable psychiatric disorder in later life, is often overlooked in geriatric medical patients. The authors evaluated the validity of two self-rating depression scales, the Zung Self-Rating Depression Scale and the Popoff Index of Depression, for 55 elderly patients. They compared these ratings with the diagnosis assigned by a psychiatrist who was blind to scale results and who interviewed these patients using DSM-III criteria. The two scales correctly classified 80% and 69% of the subjects, respectively. The authors identify six items from the two scales that may serve as a simple screening instrument for the detection of depression in geriatric medical patients.