We conducted a retrospective review to determine the early effects of implementing the American College of Surgeons (ACS) level II criteria on the number of transferrals and survival rates of trauma patients in a rurally based hospital. Data were collected from time period "B" (13 months before) and time period "A" (14 months after) implementing ACS criteria. Patient data parameters included age, sex, Revised Trauma Score, Glasgow Coma Scale score, Injury Severity Score, number of days hospitalized, diagnoses, place of injury (i.e., local county or transfer from another county), outcome, and probability of survival. There was a significant increase in the number of patients with Injury Severity Score > or = 15 from period B to period A (189 vs. 297, p = 0.002). A much higher percentage of these patients were transfers from out of county (period B = 33% vs. period A = 59.5%, p = 0.0001). Despite a higher percentage of transferred patients with probability of survival < or = 25% (period B = 25% vs. period A = 58%, p = 0.002), the survival rate in this group improved from 7.5% during time period B to 25.5% after implementing level II criteria (p = 0.0303). This data suggest that implementing level II ACS guidelines has the early beneficial effects of increasing transfers of seriously injured patients and improving survival in the most critically injured group.