We examined knowledge, attitudes, and behaviors related to skin cancer, sun exposure, sunscreen use, and use of tanning booths in 903 female and 800 male adolescents. The effectiveness of a brief, school-based intervention designed to increase teens' knowledge and preventive attitudes about skin cancer was also evaluated. Females, older students, and those with high-risk skin types were most likely to use sunscreen and to take precautions. However, overall level of protection was low. Intentions to take precautions were associated with levels of perceived susceptibility to skin cancer, attitudes about the benefits of sun exposure, skin type, and sex. Beyond intentions, sunscreen use was associated with perceived susceptibility and skin type. The one-session, school-based intervention significantly increased knowledge and perceived susceptibility to skin cancer but not behavioral intentions.