A retrospective review of 85 femur fractures sustained while alpine skiing in the north Lake Tahoe area was performed to determine incidence, severity, and mechanisms of injury. The incidence of femur fractures averaged 0.8 per 100,000 days of skiing and accounted for 0.4% of reported accidents in this series. Skiers sustaining femur fractures had a mean age of 30.2 years, significantly older than the skier mean age overall. Comminuted femoral shaft and trochanteric fractures that were the result of high-energy impact most often occurred in advanced skiers in firm or icy conditions. Firm ski conditions provided the most striking correlation to this type of fracture in the older age groups. In skeletally immature individuals (< 18 years of age), the femur fractures were mainly of the low-energy impact and minimally comminuted variety and were produced by an indirect, torsional, or bending mechanism. This injury typically occurred while skiing fast and resulted from catching the tip of a ski in wet or heavy snow. The majority of fractures (55%) occurred in the young adult population (18-45 years of age). Being predominantly advanced skiers, most of their fractures were the result of a high-energy, direct-impact fall or collision that led to severely comminuted femoral shaft and trochanteric fractures. Nineteen percent of those injured were > 45 years of age. More than two thirds of these individuals sustained fractures about the hip, typically a simple fracture in low-impact falls on hard or icy surfaces.