We describe a simple and rapid, but nevertheless precise and accurate method for measuring ethanol in serum, using the Roche Cobas Bio centrifugal analyser and the EMIT StTM serum ethanol assay reagent. Within-assay imprecision was 2.2% (CV), day-to-day imprecision was 2.5% (CV). The results correlated well with a commonly used gas chromatographic headspace method. Because of its rapidity and good practicability this method seems to be well suited for use in emergency care units of clinical chemistry laboratories.