This study reports the clinical results of treatment for injection-induced pyogenic arthritis of the shoulder joint. We followed up 13 patients who underwent operation for the treatment of pyogenic glenohumeral arthritis that developed after injections around the shoulder joint. Cultures identified Staphylococcus aureus in 6 patients and methicillin-resistant S aureus (MRSA) in 4. Finally, the University of California, Los Angeles Shoulder Score improved from 12.7 to 28.3 points. Four of the 9 patients with open surgery and 1 of 4 with arthroscopic surgery had good results; however, the other 8 patients reported poor results. Surgeons must be aware of the possibility of pyogenic arthritis when performing injections, especially in patients with underlying medical diseases. For treatment of injection-induced pyogenic arthritis of the shoulder joint, open surgery may be a better option than arthroscopic surgery.