In the last decades, concerns on protection of the environment have really increased among consumers. Initially, people were interested in discovering main environmental problems but, actually, consumers have started to exercise their decision making process in the purchase of products. We are experiencing a positive trend in accepting ecofriendly product and simultaneously consumers are reminded that environmental protection is not the only task of firms or institutions. The literature on sustainability and consumer behavior includes many studies on gender differences. The results are often contrasting. An extensive review of the research on this subject reveals that the published studies have not dealt with the substantive significance of gender differences and, as a result, the size of such differences is unknown.The present study analyses both the econometric and the substantive significance of gender differences in customer expectations, considering the “effect†of a green advertising. Therefore the aim of the research is to discover if the same advertising, with evident green and sustainable connotations, may cause different stimuli related to gender differences, to understand the presence and the dimension of different sensibilities.