Abstract Background Emergency medical vehicle collisions (EMVCs) cause significant injury, death, and property damage every year in the United States and result in significant delays in transporting patients to the hospital. Objective To identify factors associated with EMVCs that are potentially amenable to preventive intervention. Methods The authors reviewed data from the Paramedic Division of the Denver Health and Hospital Authority (DHHA) on all EMVCs occurring from 1989 through 1997. Results A T-bone mechanism, collision at an intersection, and alcohol intoxication of the civilian driver were all significant predictors of collisions resulting in injury (odds ratios of 29.7, 4.3 and 6.1, respectively, p<0.05, multiple logistic regression). Although only 75% of the division's responses are run with warning lights and sirens (WLS), a disproportionate 91% of response mode collisions were during a WLS response. The responsible EMV driver had a history of multiple EMVCs in 71% of the collisions. Conclusions Potential interventions suggested by this study include the need for EMV drivers to visually clear the intersection before entering it, alerting other drivers with visual and auditory warning systems, and attempting to make eye contact with them at an intersection. The authors recommend continued public education regarding the risks of drunk driving. The authors feel that the WLS driving mode is best reserved for patients in whom the benefits of shorter response and return times outweigh the risk of collision. Finally, the authors advocate careful review of drivers' collision history, frequent emergency vehicle operator's course retraining, and appropriate discipline when necessary.