Our purpose was to quantify and draw attention to the prevalence of extreme binge drinking rates among the nation’s high school seniors, and to examine predictors of these behaviors. We estimate that over 1 in 10 high school seniors had 10+ drinks in a row and over 1 in 20 had 15+ drinks in a row at least once in the past two weeks. This means that among high school seniors reporting 5+ drinks in a row, over half report 10+ drinks in a row; and among those who report 10+ drinks in a row, over half report 15+ drinks in a row, all within a two-week period. In addition, some sub-groups (eg, Whites, males, students from more rural areas) show particularly high rates of extreme binge drinking. Such high levels of alcohol intake clearly put adolescents at risk for injuries and fatalities from alcohol-related motor vehicle accidents, homicide, suicide, alcohol poisoning, and drowning.6