A study of motor vehicle accident deaths occurring in Napa County, California, from 1979 through 1983 showed that there was a preventable death rate of 42% for deaths that were not related to central nervous system injuries. After developing a Level II trauma center at our hospital, the preventable death rate decreased to 14%. This was statistically significant (total chi-square, 0.01 less than p less than 0.025). There was a significant increase in the average Injury Severity Score (34 versus 45, p less than 0.005) as well as significant improvements in the surgeon's response time (32 minutes versus 11 minutes, p less than 0.005) and in the time from hospital arrival to the start of surgery (3.6 hours versus 1.9 hours, 0.01 less than p less than 0.025). We conclude that these changes are indicative of improved trauma care and reflect favorably upon the effectiveness of a rural trauma center that meets Level II trauma center guidelines established by the American College of Surgeons Committee on Trauma.