In response to the negative impact of consumption on ecological sustainability, some brands have begun to practice green demarketing (GDM) – an extension of demarketing that discourages demand for products for the sake of the environment. Given the potency of consuming less in fighting environmental issues, engaging in GDM is likely to become increasingly interesting for brands that target environmentally conscious consumers. The present study adds to existing research (e.g., Armstrong Soule & Reich 2015, Reich & Armstrong Soule 2016) by examining the impact of GDM messages on attitudes toward the ad. Moreover, we shed light on the processing of GMD messages. We propose two opposing mechanisms that affect consumer’s attitudes towards a GDM ad message. Thus, while GDM ad messages might profit from their sustainability focus, attitudes toward GDM ad messages are also likely to be compromised by low processing fluency and increased skepticism. Results showed that attitudes toward sustainable ad messages were significantly higher than attitudes toward the non-sustainable ad message. Additionally, results revealed a positive and significant direct effect of GDM ad message on attitudes toward the ad and a negative significant indirect effect mediated serially by processing fluency and skepticism on attitudes toward the ad.