Objectives: To correlate cytological grades with histological grades of intraepithelial lesions of uterine cervix following The Bethesda System (TBS) of classification To evaluate different parameters used for the cytodiagnosis and cytological grading of cervical intraepithelial lesions with a review of literature Material and Methods: Cytology smears of uterine cervix and cervical biopsies from female patients received during a two year period were included for this prospective study. Cytology smears were stained by Papanicolaou stain, and histological sections were stained with hematoxylin and eosin. Both were evaluated following TBS classification of cervical intraepithelial lesions. Utility value of different parameters used for cytodiagnosis and cytological grading of intraepithelial lesions was considered with a review of literature. Results: Cervical Cytology smears and biopsies from 543 female patients were available for this study. By histology, 93 were LSIL, 26 were HSIL, 27 were invasive squamous cell carcinoma, and 397 were nonneoplastic lesions. By cytology, 114 were LSIL, 49 were HSIL, 27 were invasive squamous cell carcinoma, and 353 were nonneoplastic lesions. Conclusion: Dyskaryosis is the hallmark of precancerous lesions and invasive cancer of the uterine cervix. Histological grading on cytological smears, based on cytoplasmic differentiation, is a prediction vulnerable for grading errors. Dyskaryosis and proliferation markers are two parameters, when considered together, hopefully useful for classification and grading of the intraepithelial lesions.