Given the adverse societal and ecological impacts of oil and gas operations, health, safety and environmental issues are increasingly considered at all stages of petroleum production, especially in the early design stage. These developments stem from calls for greater attention to be paid to the integration of sustainability in organisations. Indeed, the legitimacy of organisations in the oil and gas industry is intrinsically tied to changing global societal expectations of corporate responsibility. As such, this paper is focused on exploring the progression of the sustainability logic through the societal and organisational fields, and the resultant change in an engineering design firm servicing the oil and gas sector. A framework was developed to draw attention to the role of institutional mechanisms in the institutionalisation of sustainability, and to examine discourse and control technique change. Concepts from neo-institutionalism provided the basis for the theoretical framework used in this study to analyse institutionalisation from macro as well as micro perspectives. The case study method was employed and analysis was conducted on multiple sources of data. Institutionalisation was found to be a recursive process involving the interplay of ideals, discourses and techniques across institutional realms. The study showed that while a modification of the sustainability ideal has caused loose coupling in the oil and gas organisational field, institutional work by reflexive agents in different realms is slowly bringing about tighter coupling through discourses and techniques. Techniques in the form of formal and informal management controls are seen to both affect and be affected by sustainability institutionalisation. Accordingly, the present study captures the complexity of the sustainability institutionalisation process through multiple levels of analysis, both within and between the societal, organisational field and organisational levels.