Tobacco use is the single leading preventable cause of death in the United States. Preventing initiation of tobacco use is a public health priority. Approximately 80% of persons who use tobacco begin before age 18 years, and the prevalence of cigarette smoking among high school students nationwide increased during the 1990s. This report presents findings of a study that examined trends in cigarette smoking among high school students in 11 states that collected Youth Risk Behavior Survey (YRBS) data during the 1990s. In six of the 11 states, the prevalence of current smoking and frequent smoking increased among high school students.