Suicide rates for adolescents 15-19 years of age have quadrupled from 2.7 per 100,000 in 1950 to 11.3 in 1988 (1,2). Data from earlier decades are not available to assess similar trends in rates of attempted suicide in this population. Attempted suicide is a potentially lethal health event, a risk factor for future completed suicide, and a potential indicator of other health problems such as substance abuse, depression, or adjustment and stress reactions (3). This report examines self-reported data to estimate the annual prevalence of suicidal thoughts and behaviors among U.S. high school students.