Market-based development programmes can help people living in poverty benefit from markets and lift themselves out of poverty. However, many such approaches do not pay attention to power imbalances that perpetuate marginalisation and poverty. To reach their fullest potential, market-based programmes should actively strengthen the power of marginalised smallholders and women. Major events in the market system, induced by changes in policy, regulation, social movements or business models can provide opportunities to intervene and rebalance power. Market-based programmes should also be complemented by non-market interventions that address poverty and sustainability issues in household and environmental systems. Through its work, Oxfam has encountered some of the challenges and limitations of market-based approaches. This paper is intended to raise these challenges with the broader community of development practitioners employing market-based approaches and share approaches Oxfam has taken to addressing them. The most conspicuous of these challenges is a need to address power imbalances between smallholders and larger businesses, as well as between women and men.