In this study, the authors investigated a social marketing intervention to increase the use of bicycle helmets on a university campus in the southeastern United States. Focus groups of students developed a bicycle helmet program slogan and logo (ie, "The Grateful Head"). The authors trained student bicyclists who already used helmets (n = 15) as peer agents. These agents provided bicycle helmet information and asked fellow bicyclists to sign a pledge card to wear a helmet. They gave a coupon for a free helmet to those who pledged to wear a helmet. The authors received a total of 379 pledge cards and distributed 259 helmets. Bicycle helmet use rose from a baseline mean of 27.6% to a mean of 49.3% by the last week of the intervention. (Contains 1 note.)