In this article we analyze the way that trust evolves in organizations and how it influences cooperation and teamwork. We propose that the experience of trust is determined by the interplay of people's values, attitudes, and moods and emotions. Then, using the perspective of symbolic interactionism, we examine how trust evolves and changes over time, describing two distinct states or forms of trust: conditional and unconditional. We look, too, at the factors involved in the dissolution of trust. Finally, we explore the relationship between trust and an important component of organizational performance and competitive advantage: interpersonal cooperation and teamwork.