There is no consensus of opinion about the frequency of associated nerve lesions in anterior shoulder dislocations and fractures of the proximal humerus. We undertook a prospective study to assess the incidence, the severity of the nerve injury and the diagnostic value of electromyographic examination; 215 patients were included. We performed neurological examination and needle electromyography (EMG). Nerve injury was graded according to a denervation score at the EMG. EMG disorders were seen in 133 patients (62%). Testing of sensibility and clinical reflexes proved not to be a reliable indicator for EMG abnormalities. Detection of axonal lesions by grading muscle strength based on the MRC score after these shoulder traumas is difficult. The findings of this study imply that by clinical examination alone a large number of axonal lesions remain undetected.