Abstract: Consumers are increasingly interested in environmental issues, which has raised their expectations of firms’ environmentally conscious efforts. The purpose of this study is to investigate how green messages in advertisements conveying a firm’s commitment to the environment can effectively influence consumer attitudes and behavioral intentions. Further, this study examines the psychological mechanism underlying such an effect. The results of two studies show that firms’ eco-friendly efforts as revealed in advertisements for luxury products generated favorable attitudes in consumers and increased their behavioral intentions more than firms’ eco-friendly efforts as revealed in advertisements for mass products. This process was driven by trust in the ad message, especially for consumers of luxury brands and who are not confused by green messages. This research provides empirical evidence that green ads presenting a firm’s commitment to the environment can effectively influence consumers when brands are used to promote eco-friendly products in luxury markets.