Background: To determine the frequency of dysplastic lesions in the endocervical curettage (ECC) specimens of women with ASC-US and LSIL Pap and to evaluate the possible factors associated with high grade dysplasia in those ECC specimens. Materials and Methods: Two hundred and sixty patients with ASC-US and LSIL cytologic smears who underwent an ECC at the time of colposcopic examination during January 2010 and December 2012 were reviewed. Demographic and clinicopathologic data were collected. Multivariate analysis using binary logistic regression was used to identify factors that might be associated with high grade endocervical dysplasia. Results: The frequency of endocervical dysplasia was 7.7% (20 out of 260 patients). Cervical intraepithelial neoplasia (CIN) 1 and CIN 2-3 lesions in the endocervical canal were observed in 12 and 8 patients, respectively. No microinvasive or invasive cervical cancers were identified. There was no difference in the frequency of high grade endocervical dysplasia between the patients with satisfactory and unsatisfactory colposcopic examinations (1.4% vs 5.1%, respectively, p=0.087). A multivariate logistic regression analysis demonstrated a significant association between high grade CIN on ectocervical biopsy as well as LSIL cytologic smears and high grade dysplasia in endocervical canal (OR=0.046, 95%CI=0.007-0.288; p=0.001 and OR=0.154, 95%CI=0.025-0.942; p=0.043, respectively). Conclusions: The frequency of high grade endocervical dysplasia in women with ASC-US and LSIL cytologic smears was low. Therefore, routine performance of ECC in those women is debatable. High grade ectocervical dysplasia and LSIL cytologic smears may be used as predictors for high grade dysplasia in endocervical canal and ECC in these patients is reasonable.