OBJECTIVE: To test the effect of a behavioural economics intervention in two food pantries on the nutritional quality of foods available at the pantries and the foods selected by adults visiting food pantries. DESIGN: An intervention (SuperShelf) was implemented in two food pantries (Sites A and B), with two other pantries (Sites C and D) serving as a control for pantry outcomes. The intervention aimed to increase the amount and variety of healthy foods (supply), as well as the appeal of healthy foods (demand) using behavioural economics strategies. Assessments included baseline and 4-month follow-up client surveys, client cart inventories, pantry inventories and environmental assessments. A fidelity score (range 0-100) was assigned to each intervention pantry to measure the degree of implementation. A Healthy Eating Index-2010 (HEI-2010) score (range 0-100) was generated for each client cart and pantry. SETTING: Four Minnesota food pantries, USA.ParticipantsClients visiting intervention pantries before (n 71) and after (n 70) the intervention. RESULTS: Fidelity scores differed by intervention site (Site A=82, Site B=51). At Site A, in adjusted models, client cart HEI-2010 scores increased on average by 11.8 points (P<0.0001), whereas there was no change at Site B. HEI-2010 pantry environment scores increased in intervention pantries (Site A=8 points, Site B=19 points) and decreased slightly in control pantries (Site C=-4 points, Site D=-3 points). CONCLUSIONS: When implemented as intended, SuperShelf has the potential to improve the nutritional quality of foods available to and selected by pantry clients.