Background: In this case we describe the rare and not previously documented presentation of cystitis cystica as a large solitary cystic lesion within the bladder wall. Case Presentation: We present a case of a 46-year-old Russian male with a history of lower urinary tract symptoms and suprapubic pain. CT urogram showed a 5.8 cm filling defect/cystic mass related to the base of the bladder and prostate with 8 mm thick wall. The patient underwent cystoscopy and contrast study of bladder lesion with urethral dilatation and transurethral deroofing of bladder wall cyst under general anesthesia. A histologic diagnosis of cystitis cystica was made. Conclusion: This case described the rare presentation of a large solitary bladder cyst arising from the anterior bladder wall, identified histologically as cystitis cystica. Cystitis cystica presenting as a large cystic lesion of the bladder wall is rare; however, a diagnosis of cystitis cystica should be considered in unexplained cystic defects of the bladder wall.