The purpose of this thesis is to explore Social Engineering and how marketing communications may be able to affect it. This research takes a step back from other research in the area and considers the decision makers behind Social Engineering, instead of Social Engineering interventions. One way for stakeholders to influence Social Engineering is through influencing the initial decision of which Social Engineering intervention to use. The influence of marketing communications is considered using diffusion theory, which uncovers how marketing communications diffuse through and influence a decision making group. First, the research uncovers the Social Engineering Decision Making Process. This is the decision making process of Governments for Social Engineering Decisions. The Social Engineering Decision Making Process is the combination of Podgórecki’s Sociotechnical Paradigm (1990) and Roger’s Innovation Diffusion Process (2003). The research then explores this framework through its illustration in a retailing context. The Social Engineering intervention chosen for this research is the shop trading hour legislation in New Zealand. The Social Engineering decision studied is the decision to introduce Sunday trading through the Shop Trading Hours Act Repeal Act (1990). An historical analysis explores the Social Engineering of shop trading hours, in line with an Historical methodology and Constructivist and Hermeneutic viewpoint. This narrative is created through document analysis and semi-structured in-depth interviews with five different stakeholder groups from the decision to introduce Sunday trading. The historical narrative also illustrates the Social Engineering Decision Making Process. Lastly, to uncover the influence of marketing communications and the media on the Social Engineering Decision Making Process, a content analysis of marketing communications and media over the time of the decision to introduce Sunday trading occurs. Government discussions and reports regarding the decision are also analysed. If the communications influence the Government discussions, then their themes would be present in Government documents directly following the communications. The results lend support to the Social Engineering Decision Making Process. Results outline the aspects of the legislative process that reflect each stage of the Social Engineering Decision Making Process. Findings also find support for the influence of Marketing communications and media on the Government’s decision making. The three most effective times for stakeholders to try to influence the process, through either mass or interpersonal communications are also identified.