For many years now, behavior change projects and research on pro-ecological behavior seem to have encountered difficulties in answering the question: why do people fail to act? That is, what are the barriers and constraints that prevent people from acting in a pro-ecological way? In order to fill the gap, this paper aims to operationalize the concepts of barriers and constraints, based on an approach that considers the role of behavioral goals ("to achieve X"). In addition, it aims to present a preliminary approach focused on understanding the processes involved in the barriers and constraints emergence and their consequent effect on the implementation of behavioral goals into behaviors. This is done in order to allow for a better understanding of: (1) how the interaction between individual/dispositional characteristics andthe characteristics of the situation in which individuals are in, may result in the inhibition/constraining of pro-ecological goals implementation into behaviors; and (2) the role of conscious and unconscious processes in this. Examples of barriers and constraints will be given, in order to make salient the need for future research to address these and for behavioral change projects to take them into consideration.