Blood was obtained from a sample of 976 men and 114 women. The concentration of alcohol in blood was determined by headspace gas chromatography. Results were compared for men and women as a function of age and blood alcohol concentration (BAC). The mean BAC for male driving under the influence (DUI) suspects was 1.88, compared to 1.86 for females. The relationship between beta-slope (y) and BAC (x) was y = 0.175 + 0.009x, with a small positive correlation and standard estimate of 0.049 mg/ml. The mean beta- slope for female DUI suspects was 0.214, compared to 0.189 mg/ml/h in male suspects, and this small difference was statistically significant. The overall mean rate of alcohol elimination from blood in drinking drivers was 0.191, and the 95 percent limits of agreement ranged from 0.09 to 0.29 mg/ml/h. The value of the beta-slope was slightly steeper starting from a high initial BAC but was not substantially influenced by age. The very high mean BAC in both male and female suspects indicated that these individuals had a drinking problem and that many were chronic alcoholics. 33 references, 2 tables, and 4 figures