Brachial plexus injuries (BPIs) caused by shoulder dislocation usually have a transient character and tend to resolve spontaneously. However, in some patients the symptoms can persist and require operative intervention. This work aims to determine the risk factors for persistent BPIs resulting from shoulder dislocation. The study comprised 73 patients (58 men, 15 women; mean age: 50 years) treated operatively between the years 2000 and 2016 for persistent BPIs resulting from shoulder dislocation. Patient age, gender, type of initial trauma, number of affected nerves, presence of accompanying injuries, and time interval from dislocation to its reduction were analysed. Elderly patients more often sustained multiple-nerve injuries, while single nerve injuries were more often observed in younger patients. Injury to a single nerve was diagnosed in 30% of the patients. Axillary nerve was most commonly affected. Fracture of the greater tuberosity of humerus coincided with total BPI in 50% of the cases. Longer unreduced period caused injury to multiple nerves. Analysis of our patient group against relevant literature revealed that persistent BPI after shoulder dislocation is more common in older patients. Injuries to ulnar and median nerves more often require operative intervention due to low potential for spontaneous recovery of these nerves.