From 1981 to 1989, 323 patients whose diagnoses resulted from ski injuries were emergently admitted to a Class 1 Trauma Hospital. Of this group, 107 (33%) were injured in skier-tree collisions. This tree collision group (TC group) was compared with a group that did not hit a tree (non-tree-collision group or NTC group). The average age of the TC group was 26 years, compared with 31 years in the NTC group. The Revised Trauma Score (RTS) was recorded for each patient. The TC group's average trauma score was 7.205, compared with 7.7395 for the NTC group. The Injury Severity Score (ISS) was also recorded. The TC group's ISS averaged 14.7, compared with 9.1 for the NTC group. Both of these scores demonstrated statistical significance. Certain injuries such as skull fractures, head injuries, pelvic fractures, and chest injuries (including rib fractures, pneumothoraces, and pulmonary contusions) were more common in the TC group. Tibia fractures were more common in the NTC group. Femur fractures and upper extremity fractures were evenly distributed between the two groups. Seven deaths were recorded in the TC group and five deaths occurred in the NTC group.