This article discusses endogeneity bias as it applies to causal inference in social work research. Drawing upon on both traditional economic and econometric perspectives as well recent conceptual discussions within allied fields (e.g., public health), we define and discuss key sources of endogeneity bias, summarize a variety of methods that may ameliorate such bias, and discuss the applicability and appearance of these methods in social work research. Social work research may be especially prone to various sources of endogeneity bias given the nature of the research problems investigated, the emerging state of social work measurement, and the necessary reliance on nonexperimental methods to test for explanatory (e.g., intervention) effects. We argue for heightened attention to endogeneity bias given the ever-increasing calls within social work for change-intensive evidence-based programs and policies.