Literature suggests that opportunism in strategic alliances reduces performance by limiting collaborative opportunities, inciting retaliation, and causing reputational damage. While acknowledging that this is likely when opportunistic behavior is egregious, we suggest that modest instances of opportunism may not follow the same pattern. Building from in-depth interviews with alliance managers, we underscore how opportunism can occur at varying levels of intensity that may generate different performance outcomes. We argue that mildly opportunistic behavior can enhance performance through superior private benefits in addition to common benefits; while preserving or increasing future performance. By illustrating how opportunism can be beneficial, we demonstrate that it is a more complex behavior than extant strategic alliance research may imply