In a still continuing prospective study, the possible effects of the speed of the vehicle and/or the use of helmet on the incidence of injuries to the head, face and neck were studied. The present study population comprises 223 victims of snowmobile injuries transported to one of the three hospitals in Finnish Lapland since January 1, 1991. All information was acquired from the victim or relatives on admission. The speed of the vehicle on the occasion of the accident was reported to be or = 90 kmph in 8% of the cases. Use of a protective helmet was reported in 65% of the accidents. Trauma to the head, face and/or neck occurred in 33/223 accidents, i.e. 15%. The speed was in the two highest categories in eight of the nine cases with neck injuries; six patients were reported to have used a helmet. Injuries to the face seemed to occur at lower speed; 11 of the 13 injuries were in the two lower categories, while seven victims did not use a helmet. Head injuries occurred in 11 cases with the speed poorly reported. A helmet was used by only four of the 11 victims. In conclusion, the helmet seems to protect from head injury, but its effect seems controversial in neck injury. The reported helmet use is high in Finnish Lapland.