The Boston Middle School Corner Store Initiative (CSI) brought together schools, businesses, and community partners to develop, implement, and evaluate a multicomponent pilot program designed to promote healthier beverage purchasing at corner stores among 3,500 middle school students living in Boston, Massachusetts. Healthy drinks were defined for the purpose of this initiative as plain water, low-fat and fat-free milk, and 100% fruit juice. To accomplish the goals of the CSI, partnerships between middle schools and nearby corner stores in support of healthy beverage choices were formed; a social marketing plan aimed at middle school students was developed; local corner stores and schools engaged in the social marketing plan; school-based educational and motivational components were implemented; and parents were provided with information about the campaign. The purpose of this article is to describe the: (1) design and implementation of the CSI with a focus on developing relationships across the varied partners (i.e., school, business, and community/researchers); (2) initial process and outcome evaluation data of this pilot study; and (3) lessons learned and directions for future replication and program development. (Contains 1 figure and 1 table.)