Despite their widely recognized benefits, integrative approaches to negotiation have seldom been effectively used in interorganizational negotiations. This study analyzes the 1987–1995 Korea–United States Trade Negotiations, identifying elements in those talks that could have moved the negotiations in a more integrative direction. The role of building relationships — especially between key negotiators — is examined. Informal negotiations between the key negotiators from both sides were crucial in building such relationships, which helped both sides create solutions for mutual gains. This process was realized, inter alia, by the dual role that the key negotiators took on as negotiators and as mediators.