Workers and environmentalists in the United States have often found themselves on opposite sides of critical issues. Yet at the WTO meeting in Seattle in November 1999, they came together in a historic protest many see as a watershed in the formation of a new blue-green "Seattle Coalition." However the two camps are again in conflict over substantive issues, and in the changed political climate of post 9-11, the question arises of the coalitionÕs durability. The paper first briefly reviews the history of labor-environment interactions in the United States. It then examines a series of problems and potential areas of promise for the movements: difficulties of coalition-building, expectations of reciprocation, local vs. national connections, and the question of differing class cultures and interests. Finally, three areas of potential research and action are suggested: new roles for the mainstream environmental groups, just transition alliances and climate justice alliances. We propose that the environmental justice and environmental health wings of the green movement are more suited to making long-term coalitions with labor than are habitat-oriented green groups.