The imaging of the brachial plexus (BP) cannot easily be achieved because of the extension of the region to be studied, the different tissue compositions of the adjacent anatomic structures and the necessity to work with thin tissue slices. Here is a description of the brachial plexus MRI (bpMRI) protocol that we use for the pre-operative evaluation of patients affected by the following brachial plexus (BP) pathologies: neoplastic, post-traumatic, inflammatory. The surgical implications are discussed. A survey was done on 115 patients (66 males; 49 females; mean age 46.4 years old), which underwent a bpMRI over a 32-month period (32 post-traumatic, 26 neoplastic, 25 affected by inflammatory diseases). Our bpMRI protocol is evaluated according to each mechanism of disease. The bpMRI provides a topographic localization of the tumour showing the nerve dislocations or infiltration by the neoplasm. In traumatic patients we suggest that the bpMRI could be useful to detect the degree of axonal damage when the nerve lesion is in continuity. We also consider the diagnosis and the possible surgical implications for the inflammatory plexopathies. In conclusion, a standardized bpMRI protocol has an invaluable diagnostic value for the surgeons and neurologists. It is only limited by its duration (at least 45 min).