Human papillomaviruses are etiologic for cervical cancers and their pathologic precursors. As presented in this review, pathologic, epidemiologic, and molecular data all support a working model that accounts for the pathogenetic role of these viruses in cervical neoplasia. Diagnostic criteria and classification systems are discussed in light of this model. These insights point to a potential change in clinical screening systems for cervical cancer. In addition, vaccine trials for oncogenic HPVs have begun. In the long term, these trials may hold promise as truly specific preventive therapy for this common human cancer.