To clarify the clinical significance of uterine cervical cytology during pregnancy, we analyzed the incidence of cervical cytology and its accuracy. Of the 1,593 pregnant women underwent cervical cytology, the patients with abnormal cytology were followed up and performed histological confirmation on colposcopic biopsy specimen. An incidence of abnormal cytology and cervical neoplasm during pregnancy were 1.63% (26 cases) and 0.82% (13 cases), respectively. The incidence of abnormal cytology in the pregnant women was significantly higher than that (0.9%) in mass-screened, non-pregnant 214,375 women under the age of 45 years (P < 0.001). There was no significant difference of the incidence of cervical neoplasm between in the pregnant women and in mass-screened, non-pregnant women (0.82% vs. 0.46%). The accuracy of cervical cytology during pregnancy was 45.0% and this was not significantly different from that (27.6%) in the mass-screened, non-pregnant women. Since, cervical screening cytology for uterine cervical cancer in the pregnant women as shown in this study, has an equal effectiveness to that in the mass-screened non-pregnant women, routine cervical cytology is highly recommended to performed during pregnancy. In addition, management of pregnant women with abnormal cytology was discussed in this article.