Many tissues have been analyzed for their relevance in prediction of blood ethanol concentrations, with varying results. Synovial fluid is contained and protected by the bursa sac. Because of its high water content, it may be a suitable biological fluid for analysis if a linear correlation could be established between blood and synovial fluid ethanol concentrations. Blood-synovial fluid ratios of ethanol in 28 human cadavers, using an internal standard, exhibit a good distribution ratio with an average of 0.99 +/- 0.29 and a correlation coefficient of 0.89. This study shows that synovial fluid is a good alternative biological sample for prediction of blood ethanol levels within a range.