OBJECTIVE: Review of epidemiological data on pre-invasive cervical lesions. MATERIAL AND METHODS: Literature review and analysis of data from our Department. RESULTS: Prevalence of data on preinvasive cervical lesions varies widely and depends on factors such as differences among countries or regions and among ethnic groups, and especially, differences in the type of population studied. Most important risk factors are: number of sexual partners, smoking, contraceptive use, HPV, age at first intercourse, and screening. CONCLUSIONS: In order to reduce risk, pap smears should be performed regularly, safe sex practices should be recommended, and the use of tobacco products should be avoided.