In the Province of Udine, Northeast Italy, mortality from road accidents is 37% higher than in the country as a whole. To identify the major risk factors for fatal crashes in this area, we analyzed the Police reports of 10,320 road traffic accidents that occurred from 1991 to 1996. Logistic regression was used to evaluate the association of characteristics of drivers and accidents with accident severity. The risk of involvement in fatal rather than non-fatal accidents was lower among females than among males (odds ratio (OR) = 0.65; 95% confidence interval (95% CI), 0.53-0.80). Compared with subjects < 30 years of age, subjects aged > or = 65 had a significantly increased risk of fatal injury as pedestrians (OR = 10.87; 95% CI, 4.45-26.54), car drivers (OR = 1.85; 95% CI, 1.08-3.18), moped riders (OR = 3.53; 95% CI, 1.42-8.78), and bicycle riders (OR = 7.72; 95% CI, 2.56-23.29). In accidents that occurred from 1:00 to 5:00 h the risk of death was higher than from 6:00 to 11:00 h among pedestrians (OR = 8.88; 95% CI, 2.58-30.52), car drivers (OR = 4.95; 95% CI, 3.09-7.95), motorcycle riders (OR = 13.44; 95%CI, 2.54-71.05) and moped riders (OR = 8.76; 95% CI, 2.42-31.69). Risk of death among pedestrians, car drivers, moped, and bicycle riders was also significantly increased on roads outside the urban center. Driver's injury was strongly associated with lack of use of seat belts (OR = 13.27; 95% CI, 9.39-18.74, for fatal injury; OR = 2.49; 95% CI, 2.17-2.86, for non-fatal injury). Simple interventions focused on protecting the weakest road users and based on law enforcement, behavioral change and environmental modification might result in reducing the significant excess of road traffic accident mortality found in the study area.