Background: Primary prevention of skin cancer must start early in life to reduce total lifetime sun exposure and severe overexposure in childhood. Childhood is an excellent time to form life-long prevention habits. A school-based curriculum can be an effective prevention strategy.

Objective: Our purpose was to determine the effectiveness of a skin cancer prevention curriculum at increasing knowledge and attitudes supporting prevention and decreasing sun exposure by children in grades four, five, and six.

Methods: Twenty-four classes (N = 447 students) from four public elementary schools in southern Arizona participated. Half received a pretest, half were tested at the conclusion of the 5-week curriculum in early spring, and half were tested 8 weeks later in late spring. Objective measures of suntanning were obtained.

Results: The curriculum increased knowledge about skin cancer prevention and attitudes supporting prevention and decreased suntanning. Self-reported preventive behavior was inconsistent and only weakly associated with measures of suntanning.

Conclusion: The curriculum was effective at increasing skin cancer prevention. Resulting reduction in sun exposure was superior to that achieved with previous prevention curricula. Change in attitude needed time to emerge, appearing after 8 weeks. Self-reported preventive behavior by children in elementary school may lack validity. Pretesting did not alter effectiveness. Sixth-graders may be ready for more advanced content, but the curriculum is probably too advanced for kindergarten through third grade.