Relational governance and control mechanisms are important means of managing interfirm relationships. Yet, the effectiveness of different governance mechanisms remains equivocal, especially in the international context. In this study, the authors investigate the value of relational and control governance across relationship length. Using a survey of 217 export ventures from China, they find that relational governance is not effective for short-term relationships but that it becomes effective in the long run. Output control improves export performance across short- and long-term relationships, whereas process control has its limits and weakens export performance for short-term relationships. In addition, the findings show that relational governance positively moderates the effects of output and process control on export performance for long-term relationships.