Binge drinking as a researchable construct has generally been defined as 5 or more drinks on one occasion. However, no study has been conducted to determine if the binge concept that implies “excessive drunkenness” is being optimally captured within that level. Random interviews with breath tests of drinkers returning from visiting bars in Tijuana provide both blood alcohol concentration (BAC) measurements and the self-reported number of drinks consumed. Results indicate that currently used definitions of binge drinking predict relatively low BACs and may not be capturing the “excessive drunkenness” quality of the term. Consumption duration may explain the lower BACs.