This article presents the results of research into an understanding of the conditions in which the social construction of information systems in the Brazilian banking sector is developed. It analyses the implementation, use and enhancement process of three information systems at two banks in Brazil. The research was based on the assumption that information technology is a social construction phenomenon, with a structure of use created in practice. Data were collected through observation, analysis of documents and 46 interviews. A process of social construction was found that produced four types of use of information systems. The system adoption was influenced by the confluence of individual and organizational objectives and by the type of training applied. System updates and reviews seem to follow structures of conformism to what was institutionalized by the organization and of conformity with the process of requests for enhancements.