Copyright © Taylor & Francis Group, LLC. Taking vacations in sunny locations is associated with the development of skin cancer. This study tested a multi-component sun protection intervention based on diffusion of innovations theory and transportation theory designed to increase vacationers’ comprehensive sun protection, i.e., use of clothing, hats, and shade, and use, pre-application, and reapplication of sunscreen. The trial enrolled 41 warm weather resorts in North America in a pair-matched group randomized pretest–posttest design and assessed samples of adult vacationers at resort outdoor recreation venues regarding sun protection at pretest (n = 3,531) and posttest (n = 3,226). While results showed no overall effect of the intervention on comprehensive sun protection across venues, the intervention produced statistically significant improvements in sun protection at waterside venues (pools and beaches). The intervention’s overall effects may have been impeded by a lack of uniformly robust implementation, low interest in skin cancer prevention by guests, or shortcomings of the theories used to create prevention messages. The intervention may have worked best with guests in the highest-risk recreation venue, i.e., waterside recreation where they exposed the most skin. Alternative approaches that alter resort organizations, such as through changes in policy, environmental features, or occupational efforts might be more effective than targeting vacationers with behavior-change messages.