Land expansion by existing smallholder farmers (SHFs), aka stepping-up, is a major pathway to the rise of medium-scale farmers (MSFs) in Africa. In this paper, we investigate if and how armed conflicts constrain the ability of SHFs to transition to MSFs. We find that increased conflict intensity reduces the likelihood that a SHF will expand to a larger scale, especially for farmers who rely mostly on farm incomes, rather than off-farm incomes, for their livelihoods. These findings uphold other evidence that peace and stability influence private investment, including land-based investments, that are associated with economic transformation.