A 24-year-old woman with shoulder pain had an expanding gas-containing radiolucency adjacent to the glenoid. She had been treated with prednisone intermittently for asthma. After unsuccessful attempts at percutaneous drainage, open exploration was performed with resection of a bursa containing gelatinous material and gas bubbles. The culture grew Neisseria mucosa, an organism that infrequently causes infections and is often categorized as nonpathogenic. This case illustrates that soft tissue gas accumulation is not always ominous but may be due to fastidious low virulence organisms. Appropriate surgical drainage and persistent microorganism cultures are required for definitive diagnosis and therapy.