['To examine whether endocervical glandular involvement (EGI) by squamous intraepithelial lesions (SIL) is associated with the grade of the squamous lesion and to assess the usefulness of such association for diagnostic purposes.', 'Histologic sections from two hundred successive cases of cervical SIL were reviewed retrospectively from the archives of the Department of Pathology of a tertiary care medical center.', 'Nine of 93 (9.7%) low-grade lesions and 41 of 107 (38.3%) high-grade lesions showed glandular involvement (P = 0.001, Chi-squared test). The relative risk of having EGI in high-grade lesions as compared to low-grade lesions was 3.95.'] Is endocervical glandular involvement associated with high-grade SIL?