The Papanicolaou smear is a well-established component of preventive health protocols for women. The purpose of this screening tool is to detect precursor lesions of invasive cervical carcinoma; however, the natural progression of these lesions is unclear, and it currently is not possible to determine which of the many dysplastic findings have carcinogenic potential. Furthermore, disagreement exists concerning the time frame for the malignant transformation of dysplastic cervical lesions. Despite these concerns, cervical screening has been credited with reducing morbidity and mortality from invasive cervical carcinoma in certain populations, and almost all family physicians provide this service to their female patients. The Bethesda system of cytopathologic reporting (introduced in 1988 and revised in 1991) is designed to improve communication between pathologists and clinicians. Compared with other taxonomies, the Bethesda system allows for distinction between changes associated with inflammation and infection and those reflecting squamous cell atypia and dysplasia.