&NA;Urine cytology interpretation remains a challenging field. Although much has been written in an attempt to define criteria to distinguish reactive from malignant processes and a number of ancillary diagnostic techniques have been applied to this difficult area for the same purpose, the category of “atypical” urothelial cells is still often used at the expense of more definitive diagnoses. The correlation of urinary cytology findings with concurrent biopsy specimens is strongly recommended to improve the accuracy of the interpretation of urinary tract pathology findings. The diagnostic accuracy of lesions such as urothelial carcinoma in situ, a sometimes difficult diagnosis to make on biopsy specimens, can be significantly improved when urinary cytology findings are interpreted in conjunction with biopsies. Likewise, it is recommended that voided urine cytology specimens be submitted along with washes to better interpret the cytologic findings. The authors have delineated a set of criteria to reduce the “atypical” category and to make urine cytology interpretation more reproducible. The pertinent literature, including the value of adjunct diagnostic techniques, is also reviewed in this article.