We report seven missed traumatic posterior dislocations of the shoulder in six patients. In all seven shoulders, anteroposterior radiographs did not provide the diagnosis in the emergency room after the trauma (epileptic seizure in four patients) and diagnosis was delayed for at least 24 h. The final diagnosis was reached by clinical suspicion and computed tomography (CT) scan of the seven shoulders. Two shoulders were treated by closed reduction and three were treated by closed reduction and percutaneous pinning, although four of these five shoulders presented a defect in the humeral head involving 20%-25% of the articular surface. Two shoulders dislocated for more than 6 months were treated according to Mc Laughlin's technique modified by Hawkins instead of an arthroplasty. At a minimum follow-up of 2 years and 2 months, the functional results according to Hawkins were good in all seven shoulders. There was no recurrence of the dislocation in any patient. Radiographs showed mild degenerative changes. The establishment of indications for treatment, based on the proportion of articular surface of the humeral head involved and the time of evolution of the dislocation, needs more clinical or experimental evidence. In epileptic patients, strict control of medication is of the utmost importance.