Pap smear screening for cervical cancer has been a preventive health success. Although improved technology is increasing the accuracy of this technique, more women who have never been tested will need to undergo screening in order to further decrease the incidence of cervical cancer in the United States. The establishment of infection with high-risk genital HPV types as a causative factor in cervical cancer is a major breakthrough in understanding of this disease. Testing for the presence of high-risk HPV DNA should increase the ability to identify women who are truly at risk for cancer and true cancer precursors and to more efficiently plan further diagnostic evaluation. The 2001 revisions in TBS reflect our improved understanding of the epidemiology and natural history of cervical epithelial abnormalities and cervical cancer. These revisions are designed to facilitate communication between the clinician and the laboratory and to improve the clinician's ability to accurately interpret the cytology report and plan initial management of any abnormalities.