Sun exposure during childhood and adolescence increases the risk of skin cancer later in life. To determine the prevalence and correlates of sunscreen use among US high school students, researchers assessed data on sunscreen use, demographic characteristics, and health behaviors obtained from the 1999 Youth Risk Behavior Survey (YRBS). This survey used a three-stage cluster sample design to produce a nationally representative sample of students in grades 9–12 (N=15,349). Overall, 13.3% (95% confidence interval, +1.3) of students used sunscreen always or most of the time (ie, frequent use). Frequent sunscreen use was lower among males (8.6%, +1.2) than females (18.1%, +1.9) and among Blacks (4.8%, +1.7) and Hispanics (10.8%, +2.8) than Whites (16.5%, +1.9). Frequent sunscreen use decreased with age. Infrequent use of sunscreen was associated with other risky health behaviors, such as driving after drinking or riding in a car with a drinking driver, smoking cigarettes, being sexually active, and being physically inactive. Results indicate a need for health education interventions addressing sunscreen use that target high school students.