Objective: This study tested the efficacy of a multicomponent supermarket point-of-purchase intervention featuring in-person nutrition education on the nutrient composition of food purchases. Design: The design was a randomized trial comparing the intervention with usual care (no treatment). Setting and Participants: A supermarket in a socioeconomically diverse region of Phoenix, AZ. One hundred fifty-three adult shoppers were recruited onsite. Intervention: The intervention consisted of brief shopping education by a nutrition educator and an explanation and promotion of a supermarket point-of-purchase healthful shopping program that included posted shelf signs identifying healthful foods, sample shopping lists, tips, and signage. Main Outcome Measures: Outcomes included purchases of total, saturated, and trans fat (grams/1,000 kcal), and fruits, vegetables, and dark-green/yellow vegetables (servings/1,000 kcal) derived through nutritional analysis of participant shopping baskets. Analysis: Analysis of covariance compared the intervention and control groups on food purchasing patterns while adjusting for household income. Results: The intervention resulted in greater purchasing of fruit and dark-green/yellow vegetables. No other group differences were observed. Conclusions and Implications: Long-term evaluations of supermarket interventions should be conducted to improve the evidence base and to determine the potential for influence on food choices associated with decreased chronic disease incidence. (Contains 2 tables.)