Salesperson performance has been heavily researched in the marketing literature. Previous research has identified various personality traits, salesperson behaviors, and situational characteristics that affect salesperson performance. Results indicate that no single approach to the study of salesperson performance is sufficient by itself. This study investigated the interactions among personality, situational, and behavioral characteristics of salespeople, and their effect on salesperson performance. Since the adaptive behavior construct has been cited as a key determinant to understanding these interactions, an examination of the adaptive behavior-performance relationship was undertaken. A model of adaptive selling behavior was developed and empirically tested. An analysis of the data suggests that adaptive behavior (e.g., salesperson planning process) affects salesperson performance. ln addition, several of the situational characteristics (i.e., sales position characteristics, customer variables, salesperson-customer relationship, personal resources, and managerial variables), utilized in this study, were found to affect both adaptive behavior (i.e., salesperson planning process and customer interaction) and salesperson performance. The results of this study provide theoretical, methodological, and substantive implications concerning the adaptive behavior to performance relationships. The study concludes with suggested directions for future research. / Ph. D.