This work aimed at verifying the field of performance of nurses in the mental health services in the city of Campinas-SP as well as at analyzing their work relations with other members of the multi-professional staff as an attempt to observe the nexuses established between such professionals' practice and the service's conception concerning team work. A qualitative and descriptive investigation was conducted which used the case report as a research methodology. It was observed that nurses take different roles according to the organization of the team's work process and that the recognition of such context is essential for nursing professionals to develop their work critically and to keep high quality standards.977-82