Acute anterior shoulder dislocation is an injury in which the top end of the upper arm bone is pushed out of the joint socket in a forward direction. Afterwards, the shoulder is less stable and is prone to re-dislocation or subluxation (partial re-dislocation), especially in active young adults. Initial treatment involves putting the joint back in place. This is called 'closed reduction' when it is done without surgery. Subsequent treatment is often conservative (non-surgical) and generally involves placement of the injured arm in a sling or in another immobilising device followed by specific exercises. After a comprehensive search, completed in September 2013, for randomised controlled trials that compared different methods of conservative management of these injuries we included only four trials, one of which was not truly randomised. These trials involved a total of 470 participants (371 male). All had primary traumatic anterior dislocation of the shoulder reduced by various closed methods. Three studies evaluated mixed populations; in the fourth study, all participants were male and 80% were soldiers. All trials were at some risk of bias (systematic errors that could lead to overestimation or underestimation of treatment effectiveness), with two trials in particular being at high risk of bias in a number of aspects. Overall, the quality of the evidence was very low, meaning that we are very uncertain about the direction and size of effect. All four trials compared immobilisation of the arm in external rotation (when the arm is orientated outwards with the forearm away from the chest) versus immobilisation in internal rotation (the usual sling position, where the arm rests against the chest) following closed reduction. Investigators followed patients for at least two years. The results showed no difference between the two groups in any of our pre-defined outcomes. These included re-dislocations, scores on validated shoulder function questionnaires, return to pre-injury activity or sport, and any instability. Other pre-defined outcomes (patient satisfaction with the intervention, and health-related quality of life outcome data) were not reported. Adverse events were poorly recorded. In our recommendations for future research, we point out the importance of completing and publishing the eight other trials making the same comparison as the four included trials. We also note that other important questions need to be studied, such as how long the shoulder should be immobilised for the best outcomes. In conclusion, current evidence from randomised controlled trials is insufficient to inform choices for conservative management following closed reduction of traumatic anterior dislocation of the shoulder.