This study aims to systematically evaluate the public relations effects of policy using empirical data based on evaluation framework for PR effectiveness, focusing on mass media as the main policy communication chanel. Furthermore, derived from the emerging concept of dialog communication in public administration and public relations with regards to policy communication, this study also seeks to empirically examine how “dialogic policy communication satisfaction” influence the relationship between policy PR and public support for government policy. Specifically, the evaluation factors of policy PR effectiveness were segmented into output, outtake, and outcome in order to verify their relationship. Additionally, the study examined the impact of policy PR outcome on policy support, and verified whether this process was mediated by dialogic policy communication, composed of openness and mutuality. Data from an online survey conducted among 387 Korean adults were analyzed. The results showed that output of the policy PR had a significant direct effect on outtake and outcome, and the effect of output on outcome was partially mediated by outtake. On the other hand, the outcome had a significant effect on policy support, which is the ultimate goal of policy communication, and this process was also partially mediated by the dialogic policy communication satisfaction. Finally, it was verified that there was a hierarchical relationship between mutuality and openness of dialogic policy communication satisfaction, in which mutuality had a positive impact on policy support through full mediation of openness. Based on the results, this study provides useful practical implications for government policy communication.