The primary concern of this study is employee theft. However, beyond merely making efforts to prevent the recurrence of employee theft behavior, an equally important research objective is to move beyond the distrust between employees and employers regarding employee theft and to build healthy mutual relationships. If wrongdoing by employees exists within a corporation, it is only natural that the causes and reasons should first be diagnosed, the situation clearly understood, and remedies devised. Therefore, this study sought to clarify what employee theft is, to examine the financial losses resulting from employee theft, and to identify the causes of employee theft and feasible prevention measures. Additionally, this study introduced the types of employee theft that can occur in organizations. Until now, the causes of employee theft have been understood through either person theories or workplace theories separately. However, this study, based on social learning theory, emphasized that while dispositional and situational variables are important predictors of employee theft, the interaction effect between the two variables is even more important. That is, the study argued that the causes of employee theft should be viewed as the result of the interaction between situational opportunities and individuals' needs and attitudes. Accordingly, among all possible interaction effects between individual need variables and situational variables, the study presented three person-by-situation interaction effects deemed important for future research. However, this study has the limitation of being a preliminary study on employee theft behavior that only theoretically proposed antecedent variables and a causal model. Nevertheless, given the need for proactive measures against quasi-theft behaviors prevalent in organizations, this was an exploratory study that publicly drew attention to this issue, and it is expected that empirical studies with refined conceptual definitions and variable specifications will continue to be conducted.