Trust as a prerequisite and catalyst for cooperation has gained much scholarly attention in the past three decades. This report seeks to analyze drivers for, and obstacles to, successful project cooperation through applied theories of trust as an analytical tool. The report studies the operational level of three NorwegianRussian cooperation projects from the environmental and health spheres, using interviews with project participants as empirical data. The findings imply that socio-cultural factors are important in building and maintaining trust among the project participants, which in turn is essential for successful cooperation. In connection with this, shared identities and discourses seem to be of imporance as a common ground for building trust relationships.