Urine cytology is an excellent test for high-grade urothelial carcinoma, but it is ineffective for low-grade tumors. A multitude of ancillary tests have been developed to improve diagnostic accuracy for the wide range of urothelial neoplasms, but their value is limited to specific clinical settings. More recently, the Paris System for Reporting Urinary Cytology was introduced to improve the practice of urine cytology by recommending standardized criteria and terminology for diagnosis and discouraging the use of cytology to identify low-grade urothelial tumors.