An interesting open question is whether the adoption of formal good corporate governance policies by listed firms is mainly symbolic, or indicative of substantive implementation of good governance practices. In this paper we use data on Thai listed firms to test whether firms with higher levels of good governance policy adoption are less likely to violate listing rules and laws put in place to protect shareholders.Our results suggest that Thai firms on average substantively, as opposed to symbolically, implement recommended governance policies, as violations occur less frequently among firms with higher levels of formal good governance policy adoption. However, we do find that the negative relation between formal policy adoption and subsequent violations is significantly weaker among smaller firms, less profitable firms and "talk-only" firms that issue policy statements about good governance while lagging in the adoption of policies related to shareholders rights and the Board of Directors.