The empirical status of Tom Tyler’s (1990) process-based model of regulation is frustrated by the fact that most studies are conducted in the US, leaving open the question of whether similar effects can be observed in countries with different historical and political contexts. The current study tests two process-based model hypotheses using cross-sectional survey data from 683 young adults in Slovenia. The results reveal: (1) procedural justice judgments significantly shape individual perceptions of police legitimacy, and (2) perceived police legitimacy explains self-reported compliance with the law. Though slightly diminished in magnitude, the legitimacy effect persists when using an instrumental variable to address possible endogeneity bias and after statistically controlling for known correlates of law violating behavior (i.e., personal morality and low self-control). The findings also show that the legitimacy effect on compliance with different laws (e.g., littering and buying stolen property) varies depending on the operationalization of legitimacy (i.e., additive scale versus instrumental variable). While the findings indicate that the process-based model of regulation is germane to post-socialist countries such as Slovenia, more research focusing on the explanatory breadth of the model is necessary.