Abstract
The environmental contemporary dynamics has influenced over the adoption of more comprehensive levels of analysis so that organizational phenomena can be understood. Subjects. as network formation, strategic alliances, integration between private and public affairs and other more complex organizational structures demand studies that reach beyond the internal scope of the organizations. Among the issues of interest in this inquiry field, trust has received great attention from researchers all over the world, given its importance for the adoption of more flexible and easily adaptable governing mechanisms. The present essay aims at presenting some definitions of "trust", as well as four of the main theoretical trends that try to understanding it as a social phenomenon - rational choice, transactional costs, neo-institutionalism, and the social system theory - highlighting their core presuppositions and the contributions aimed at, guided by the dynamics of the inter organizational relationships.