This study investigates the concept of vote buying, with a particular focus on its usage in research on clientelism. Vote buying is often poorly defined. Such conceptual ambiguity may distort descriptive findings and threaten the validity of causal claims. Qualitative analysis suggests that researchers often employ the concept of vote buying differently, and regressions from Nigeria and Mexico suggest that using alternative definitions can yield divergent empirical results. This diverse usage also poses the risk of conceptual stretching, because scholars often use vote buying to describe other phenomena. To improve future research, analysts should pay close attention to the conceptualization of vote buying.