Though it may seem commonsensical that interoperability standards play an important role in systems integration and information sharing within the environment of electronic government, establishing these standards is no easy task. This process is highly complex due to the number of participating agents, the environment in which it takes place and the interrelation between the agents and the environment, not to mention the likely conflicts of interests connected with this interrelation. It is also believed that the affected agents’ perception of the relevance and the legitimacy of the defined specifications may influence the latter’s adoption. Based on these assumptions, this paper analyses the development and implementation processes of standards for electronic government from the standpoint of Institutional Theory. It presents the preliminary findings of an exploratory qualitative case study, based on document analysis and semi-structured interviews, of the framework interoperability specified by the Brazilian Federal Government (e-PING). The results point out some of the institutionalization processes and legitimacy mechanisms that are being used by the government in the establishment of those standards and the likely implications of those actions for full compliance with the said standards.