Abstract Using the negotiations of the 1979 Convention on Long-Rage Transboundary Air Pollution as a case, this article examines the characteristics of Nordic environmental diplomacy. Through a Nordic perspective, it investigates the practices, dynamics, and motives of Nordic cooperation on atmospheric pollution within an international context. It argues that Nordic environmental diplomacy was anchored in regional Nordic cooperation, facilitating a fluid and multi-layered collaboration at the international scene. By revealing this complexity of Nordic environmental diplomacy, the article nuances the diplomatic accounts focusing on single countries, emphasizing the multi-ownership of ideas and achievements. Furthermore, by exploring the motivational, organization, and practical traits of Nordic environmental diplomacy, it proposes to characterize Nordic environmental diplomacy as green internationalism, a self-interested international environmentalism resting upon a shared sense of Nordic solidarity and institutional cooperation.