Objective We report a case of shoulder dislocation after a brachial plexus block with a double-injection technique using the infraclavicular coracoid approach.

Case Report An obese woman with no previous episodes of joint dislocation developed an anterior dislocation of the head of the humerus after an infraclavicular coracoid block performed for hand surgery. Dislocation was probably because of a combination of unrecognized glenohumeral instability, paralysis of some muscles of the shoulder, and positioning of her arm on a board below her torso. Shoulder dislocation was recognized after surgical positioning of her arm, and painless reduction was achieved. There were no sequelae after 10-day follow-up.

Conclusions When motor block of the muscles of the shoulder occurs after brachial plexus anesthesia, special care must be taken in patient positioning to avoid shoulder dislocation.