This article describes agreement among diagnoses made according to five definitions of endogenous depression in a sample of 99 depressed elders and discusses the relationship among these systems and selected demographic and clinical characteristics. Poor to fair agreement was generally demonstrated, except for Research Diagnostic Criteria (Spitzer, Endicott, & Robins, 1978) and Diagnostic and Statistical Manual of Mental Disorders, 3rd ed., rev. (American Psychiatric Association, 1987), which demonstrated excellent agreement. Mostly, demographic and clinical variables (e.g., severity of depression) were unrelated to endogeneity diagnoses. The conclusion was reached that these criteria are not all measuring the same construct in older adults and that the relationship between depression severity and endogeneity should be discussed in terms of specific definitions rather than general terms.