BACKGROUND: Binge drinking (consuming five or more drinks during a drinking occasion) is responsible for more than half of the 79,000 annual deaths due to excessive drinking in the U.S. Although studies show a strong dose-response relationship between the intensity of binge drinking (i.e., the number of drinks consumed per binge episode) and adverse outcomes, there are no population-based studies assessing this measure. PURPOSE: This study aims to analyze population-based data from a module of questions on binge drinking among U.S. adults to assess the number of drinks consumed by binge drinkers and the associated independent risk factors for consuming more drinks. METHODS: Data were analyzed from 14,143 adult binge drinkers who responded to the Behavioral Risk Factor Surveillance System binge drinking module in 2003 and 2004. Total drinks were calculated by summing the total number of beer, wine, and liquor-containing drinks consumed during a respondents' most recent binge drinking episode. RESULTS: Binge drinkers consumed an average of 8.0 drinks (median 6) during their most recent binge drinking episode; 70.0% of binge drinkers consumed six or more drinks, and 38.4% consumed eight or more drinks. Men consumed more drinks during their last binge episode than women (M = 8.3 vs 7.0, median = 7 vs 6), and those aged 18-34 years consumed more drinks than those aged >34 years for both men and women. Independent risk factors for consuming eight or more drinks included being male; being aged <35 years; being other than white race/ethnicity; having less education; not being married; binge drinking three or more times in the past 30 days; and drinking mostly beer. CONCLUSIONS: Most adult binge drinkers drink in excess of the five-drink threshold defining this risky behavior. The intensity of binge drinking should be monitored regularly by health agencies to improve surveillance and to better assess the impact of interventions designed to reduce binge drinking and its consequences.