To assess the effect of an unconditional cash transfer (CT) implemented as part of an emergency response to food insecurity during a declared state of emergency. Pre-post intervention observational study involving two rounds of data collection, i.e. baseline (April 2012) and final survey (September 2012), on the same cohort of 'poor' and 'very poor' households enrolled by Save the Children in an unconditional CT programme. Aguié district, Maradi, Niger. Households with a non-acutely malnourished child aged 6-36 months (n 412). The study showed that the living standards of 'poor' and 'very poor' households improved, as indicated by a reduction in poverty-related indicators and an improvement in household food security. Anthropometric outcomes for children aged 6-36 months improved significantly, despite a decline in child health and women's well-being and autonomy. Risk factors for becoming acutely malnourished post-intervention were being from a very poor household at baseline, starting the lean season with low weight-for-height Z-score (WHZ <-1) and the presence of co-morbidity. The results of the study are consistent with the published evidence regarding the general impact of CT and suggest it is plausible that giving cash during an emergency can help safeguard living standards of the very poor and poor. While improvements in childhood nutrition status were seen it is not possible to attribute these to the CT programme. However, knowledge of the risk factors for acute malnutrition in a particular setting can be used to influence the design of future CT interventions for which a controlled trial would be recommended if feasible.