Power-sharing is a leading institutional strategy for the management of ethnic conflict. Yet its performance is uneven. It often delivers a peace dividend: stopping violence, avoiding minority exclusion, and reducing group-based insecurity. Its decision-making efficiency and governance record, however, have weaker evaluations. We conceptualize ‘the power-sharing lifecycle’ to better understand the reasons for this uneven record. Exploring power-sharing performance through a lifecycle lens helps illuminate the experiences of – and potential for – power-sharing in the post-uprisings Arab world and beyond.