Eight patients from 20 months to 79 years of age (average, 49 years) with papillary or polypoid inflammatory lesions of the urinary bladder were studied. On cystoscopic examination or initial pathologic examination, several of the lesions were thought to be neoplasms. Their clinical and pathologic features, however, were typical for papillary and polypoid cystitis. Microscopic examination disclosed thin, finger-like papillae or broad-based polypoid lesions with prominent stromal edema typically associated with chronic inflammation. The lesions were covered by, and adjacent to, urothelium that was usually normal but was occasionally metaplastic. A history of recent catheterization was present in only one case. These cases illustrate that occasional papillary or polypoid urothelial lesions are inflammatory rather than neoplastic.