Emphysematous cystitis (EC) is a severe infection of the bladder that usually affects older women with diabetes mellitus. In rare situations, EC can lead to serious complications such as necrotizing fasciitis. We report the case of a 77-year-old woman who developed emphysematous cystitis complicated with rapidly progressive, gas-producing, necrotizing inflammation located on the right lower abdominal wall. The patient had aggressive drainage and debridement in order to control the extensive necrosis. To our knowledge, this is the third case report that describes a possible association between EC and NF requiring aggressive surgical intervention for both diseases.