Motor vehicle crashes remain a leading cause of death and injury in the industrialized world. Alcohol consumption is implicated as a major factor in fatal motor vehicle crashes (MVCs), but only poor estimates of blood alcohol concentrations among nonfatally injured crash victims are available. A 3-year study was undertaken at a Regional Trauma Unit to determine the demographics, injury severity, and alcohol positivity of motor vehicle crash victims. Between August 1, 1986 and July 31, 1989, 825 motor vehicle crash victims were available for study; 368 drivers were admitted to the unit within a period of 4 hours. Of 715 patients tested for alcohol, 31.0% were positive. A total of 333 drivers were tested for blood alcohol; 128 (38.4%) were positive. The mean blood alcohol concentration (BAC) at admission for the drivers was 145.6 mg/100 ml; the estimated mean BAC at crash was 180.9 mg/100 ml. The mean age of BAC positive drivers was 31.4 years, compared to a mean age in the BAC negative drivers of 35.2 years (p less than 0.02). Male patients represented 76.6% of the drivers, yet represented 83.6% of the BAC positive drivers (p less than 0.05). There was a marked seasonal variation in BAC positivity, with 46.1% of drivers positive during the summer months. Alcohol appears to be a significant factor in nonfatal MVCs.