The purpose of this study is to examine the relationship between persuasion knowledge, skepticism toward green advertising, and consumers’ responses: a) investigating how types of persuasion knowledge (i.e., agent, tactic, and topic) are related to two types of skepticism (i.e., advertising claims and advertisers’ motives); b) indicating how both types of skepticism affect advertising credibility and attitudes; and c) exploring how the skepticism mediate between the persuasion knowledge and consumers’ responses. To verify this relationship, 217 adults were surveyed, and the data was analyzed by multiple regression. The study suggested three main results. The first result showed that agent knowledge is positively related to the two types of skepticism, while tactic knowledge affects skepticism toward advertisers’ motives. In addition, skepticism based on advertising claims negatively affects green advertising credibility and attitudes. Thus, agent knowledge is the strongest predictor of both types of skepticism, and skepticism based on advertising claims is the most influential determinant of consumers’ responses. Lastly, there are no mediation effects of both skepticism between persuasion knowledge and consumers’ responses. Based on the results of this study, suggestions regarding the marketing and advertising strategy of green products were addressed.