This study evaluated a tailored intervention to promote sun protection in parents and their children, hypothesizing that the tailored intervention would lead to improved skin cancer prevention behaviors compared to generic materials. Families were recruited through schools and community centers and were included if there was 1 child in Grades 1-3 at moderate to high risk for skin cancer. Participants were randomized into one of two intervention groups: a tailored intervention, in which they received personalized skin cancer education through the mail; or a control group who received generic skin cancer information materials. Before and after intervention, parents completed questionnaires about their and their children's skin cancer risk and prevention knowledge and behaviors. Parents also completed 4-day sun exposure and protection diaries for their child and themselves. Tailored group participants demonstrated significantly greater positive changes in prevention behavior after the intervention, including children's use of sunscreen, shirts, and hats, and parents' use of shade, and skin examinations. Effect sizes were small and perceived benefits and social norms mediated intervention effects. Findings from this study support the efficacy of focusing tailored communications to families in order to change skin cancer prevention practices in young children.