Green marketing in hotel rooms relies particularly on the hotel’s communication to the guest, with a goal of gaining the guest’s voluntary participation in sustainable programs. Developing a persuasive message, therefore, is critical to the effectiveness of the hotel’s green efforts. To explore effective in-room green communication strategies of the hotel industry, we propose application of several widely adopted information processing theories. We review relevant theories, develop key propositions for the hotel industry, and offer a theoretical framework and propositions for future research. Our content analysis of the contents of thirty-six guestroom message cards finds that many hotels are using some of these information theories, but a more scientific approach is indicated.