Actinomycosis is a chronic, granulomatous disease caused by the actinomyces species, most commonly, Actinomyces israelii. Primary actinomycosis of the bladder is rare and is usually associated with abdomino-pelvic infection and prolonged use of Intrauterine Device (IUD). On imaging, it can often be mistaken for a malignancy. We report a case of a 55-year-old female with weight loss, anaemia and chronic pelvic discharge with a history of a retained IUD. An initial Computerized Tomography (CT) revealed an adnexal mass that was pelvically resected. A rigid cystoscopy was then performed and an incidental posterior bladder wall mass revealed actinomycosis.