This chapter seeks to familiarize the readers with the Bethesda system (TBS) of reporting cervical cytology. There are overlapping cytomorphological features of severe dysplasia and carcinoma in situ; therefore, Richart RM presented the concept of cervical intraepithelial neoplasia (CIN) and classified the preneoplastic lesions of cervix as CIN 1, CIN 2, and CIN 3. The TBS of classification clubbed CIN 2 and CIN 3 as high grade squamous intraepithelial lesion (HSIL). The TBS 2001 of reporting cervical cytology smear provides uniform guidelines for reporting cervical cytology. This classification is mildly modified in 2014 Bethesda system. In any cervical smear at first overall assessment should be done regarding the clinical history, staining quality, and adequacy of the specimen. After the initial assessment of adequacy the smear should be broadly classified as negative for intraepithelial lesions and epithelial cell abnormality. A detailed description on epithelial cell abnormalities has been also provided in this chapter.