We reviewed the cases of thirty-three patients with non-union of a clavicular fracture. The patients who seemed to have a predilection to non-union were seven who had sustained a refracture and twenty-one who had had severe trauma. Eleven patients had an atrophic non-union, and these lesions were less symptomatic than the hypertrophic non-unions in the series. Only three of the eleven patients with an atrophic non-union had an operation, compared with sixteen of the twenty-two patients with a hypertrophic non-union. The results in the nineteen patients who underwent the various surgical procedures (twenty-five operations) showed that the most successful procedure was internal fixation and bone-grafting. Even though union was achieved in twelve patients who were surgically treated, mild to moderate symptoms persisted in some.