This paper focuses on hybrid board governance and the challenges faced by the board of directors when implementing social impact measurements. Interviews with 36 board chairs and general secretaries in social hybrids in Sweden show that while boards support social impact measurements, they face obstacles in implementing them. Drawing on the institutional logics framework, we identify three main reasons for these implementation problems. First, amid field level regulations focusing on cost efficiency, boards find it difficult to switch to a social impact that lacks a single metric that can be measured annually. Second, board members struggle to find sufficient time when they serve on a pro bono basis, and it is difficult to hold them accountable when limited progress occurs. Finally, acknowledging board practice variation, we highlight the need to distinguish between “beneficiary-driven” and “membership-driven” social hybrids. In the former, boards face the challenge of operationalizing the long-term benefits for end beneficiaries; in the latter, interactions with members are so operationally focused that boards struggle to maintain a long-term agenda for implementing social impact measurement. Given these challenges, we propose that future research should explicitly incorporate the board level in theorizing how hybrid organizations manage institutional logics and performance measurement.