OBJECTIVE:To determine the association between atypical glandular cells (AGC) on Pap smear and clinically significant histology, in a large health region.METHODS:A cytologic database of over one million Pap smears was reviewed for a result of AGUS/AGC. Cytologic and histologic follow up was obtained to establish the presence of significant histology.RESULTS:456 patients available for follow up had AGUS/AGC cytology results (0.043% of all Pap smear results). 197(45.2%) patients had a clinically significant diagnosis including 40 with adenocarcinoma in situ (AIS) of the cervix and 48 with endometrial cancer.CONCLUSION:AGC on a Pap smear is frequently associated with a clinically significant diagnosis.