This article addresses two problems that are often encountered in the litigation of cases involving driving while impaired with alcohol or with excess alcohol in the blood. The first is that beverage containers need to be analyzed for contents in the police station rather than the costly, time-consuming method of sending it to a forensic laboratory. The second is that it is desirable to know how accurate the labeled value of alcohol content is on the container. For the analysis, twenty-one samples of commercially sold beverages (beer, wine, and liquor) were purchased in the open market. The labeled alcohol concentrations by volume, varied from around 5 percent for beer, about 12 percent for wine, and about 40 percent for liquor. Headspace gas chromatography was used in this work as the standard accurate method. Data indicates that the headspace analysis of the beverages using the Intoxilyzer 5000C or the Alcotest 7410 GLC give values close to the correct value obtained by the GC method. The analyses can easily be performed at the location where the subject’s breath alcohol is measured. The procedure takes only a few minutes and can be performed by a trained breath technician. This is fast, convenient and accurate and avoids the time and expense of having the analyses done at a forensic laboratory. This procedure is useful for the analysis of seized unknown beverages without the manufacture’s label. Data also shows that the labeled alcohol concentration of commercially sold beverages is generally accurate to the actual value measure by GC. If the beverage seized is contained in the original container with the alcohol concentration marked, then the labeled alcohol concentration can be used for BAC calculations. 2 tables, 3 footnotes, 3 references