OBJECTIVE: To discuss return to play after femur fractures in several professional athletes. BACKGROUND: Femur fractures are rare injuries and can be associated with significant morbidity and mortality. No reports exist, to our knowledge, on return to play after treatment of isolated femur fractures in professional athletes. Return to play is expected in patients with femur fractures, but recovery can take more than 1 year, with an expected decrease in performance. TREATMENT: Four professional athletes sustained isolated femur fractures during regular-season games. Two athletes played hockey, 1 played football, and 1 played baseball. Three players were treated with anterograde intramedullary nails, and 1 was treated with retrograde nailing. All players missed the remainder of the season. At an average of 9.5 months (range, 7-13 months) from the time of injury, all athletes were able to return to play. One player required the removal of painful hardware, which delayed his return to sport. Final radiographs revealed that all fractures were well healed. No athletes had subjective complaints or concerns that performance was affected by the injury at an average final follow-up of 25 months (range, 22-29 months). UNIQUENESS: As the size and speed of players increase, on-field trauma may result in significant injury. All players returned to previous levels of performance or exceeded previous statistical performance levels. CONCLUSIONS: In professional athletes, return to play from isolated femur fractures treated with either an anterograde or retrograde intramedullary nail is possible within 1 year. Return to the previous level of performance is possible, and it is important to develop management protocols, including rehabilitation guidelines, for such injuries. However, return to play may be delayed by subsequent procedures, including hardware removal.