Urine cytology continues to play an important role in the diagnosis and management of urothelial carcinoma, a common cancer of adults with significant morbidity and mortality. Because of its high sensitivity for high-grade urothelial tumors, including lesions that may be cystoscopically occult, urine cytology nicely compliments cystoscopic examination, a method that detects most low-grade tumors. Over the decades, several reporting schemes for urine cytology have been published in the literature, each of which has relative strengths and weaknesses. Unlike cervical cytology, there has not been widespread acceptance and use of any particular reporting scheme for urine cytology studies. Thus, terminology and criteria for urine cytology reporting are not uniform among pathologists, which can frustrate clinicians and hinders interlaboratory comparisons. Cancer (Cancer Cytopathol) 2013;121:9–14 © 2012 American Cancer Society.