This article draws upon theory and a case study to research public administration’s role in environmental governance systems. Thus, it examines Brazil’s environmental regulation of the offshore oil and gas sector. The methodology used follows the Institutional Analysis and Development Framework and supports interviews, documentation review and direct observation. The results indicate the main features of the institutional setting, including the rules in use and relevant external variables. Concluding, three key elements operating at the organizational level are highlighted: the means of stakeholder participation; the stability and forms of interaction within the personnel; and the autonomy to enforce established arrangements.