Introduction: Despite the documented pros and cons of reaming, the reamed intramedullary interlocking nail (IMILN) for closed shaft of femur fractures in adults is a worldwide standard procedure. Reaming requires a careful technique and instrumentation, despite that complications related to hardware, like breakage or incarceration, can occur. We present a peculiar case of uncoiling of the flexible reamer during closed nailing for a femoral shaft fracture in a 21-year-old male, discuss the causative factors, and highlight the precautions necessary to avoid it. Such an incident has only been reported once previously and ours is the second case ever to be reported. Case description: A 21-year-old male presented to the advanced trauma center of our institute with closed fracture of the left femur. He was posted for a reamed femoral interlocking nail, wherein, during the reaming procedure with the reamer size 9.5, it got stuck and uncoiled over the beaded guidewire. The reamer was extracted with back hammering and thereon the surgery went on smoothly. The patient did well postoperatively and had union at 4 months. Conclusion: Uncoiling of a flexible reamer is a rare complication of femoral intramedullary nailing. Sequential reaming, moderate force, and appropriate instrumentation are of paramount importance. Careful consideration must be given before using the same reamer for multiple surgeries.