While there is a large literature on agricultural technology adoption, evidence from the poorest countries is still lacking and the decision-making process of farmers is still poorly understood. We empirically analyze mineral fertilizer adoption among poor and food insecure smallholder farmers in South-Kivu, eastern DR Congo, after its introduction by a research and extension program. We disentangle the adoption process in an awareness step, a tryout decision, and a continued adoption decision. We show that variables commonly used to explain agricultural technology adoption, and the different program interventions, have a different impact on the different steps in the adoption process.