Sustainability alliances are gaining momentum, enabling firms to simultaneously pursue economic profit while also generating value for society. Extant alliance literature fails to sufficiently inform this emerging phenomenon as it primarily comes from a perspective of alliances pursuing unidimensional economic goals. To build theory on governance in sustainability alliances, we conducted an explorative case study of eight sustainability alliances in Sweden. We demonstrate how the joint pursuit of sustainability introduces unique and difficult cooperation and coordination concerns in such alliances. Yet, we also showcase that it enables mission-driven alliance governance – a previously underappreciated governance mechanism, beyond relational and contractual approaches. Based on our findings, we discuss the nature of mission-driven alliance governance and how it helps to improve cooperation and coordination outcomes.