Objectives. This study examined the role of price on purchases of low- fat snacks from vending machines. Methods. Sales of low-fat and regular snacks were monitored in nine vending machines during a 4-week baseline, a 3- week intervention in which prices of low-fat snacks were reduced 50%, and 3 weeks postintervention. Results. The proportion of low-fat snacks purchased was 25.7%, 45.8%, and 22.8% in the three periods, respectively. Total snack purchases did not vary by period. Conclusions. Reducing relative prices may be effective in promoting lower-fat food choices in the population. Vending machines may be a feasible method for implementing such nutrition interventions.