We have reviewed the history of 154 primary, traumatic dislocations of the shoulder in order to determine the risk of recurrence. We found a recurrence rate of 68% in patients under the age of 20, after a follow-up period of 1-9 years (average 4.5 years). There was a highly significant difference (p < 0.0001) in the recurrence rate of patients under, and above, 30 years of age. Twenty per cent of the patients had a concurrent minor fracture at the shoulder with 2 out of 39 of the recurrent cases (5%) and 29 of the 115 non-recurrent cases (25%); this is also a significant difference (p < 0.01). Neither the need for general anaesthesia at primary injury nor the occupation of the patient was a relevant factor in the final outcome of the dislocation. Four nerve injuries were encountered (3%), with no severe sequelae at follow-up. The young patient with no concurrent fracture at the time of the primary shoulder dislocation has a high risk of recurrence.