We report three cases of fracture of the humerus that occurred at the tip of interlocking humeral nails inserted previously for humeral shaft fractures. The fractures occurred at 8, 10, and 26 weeks postoperatively, and all occurred through the distal interlocking screws after the patient sustained a rotational force to the arm. All three patients had further surgery, two subsequently healed their fractures, and one is still in active treatment. Orthopaedists should be aware of this complication when choosing interlocking humeral nails for the treatment of humeral shaft fractures.