High-risk HPV (hrHPV) and cytology co-testing is utilized for primary cervical cancer screening and for enhanced follow-up of women who are hrHPV-positive, cytology negative. However, data are lacking on the utility of this method to detect pre-cancer or cancer in community-based clinical practice. This study describes cytology and hrHPV results preceding high-grade cervical intraepithelial neoplasia, adenocarcinoma in situ, or cervical cancer (i.e., CIN2+) in an integrated health system employing routine co-testing among women aged 30 years and older. We conducted a cross-sectional analysis of adult female members of Kaiser Permanente Northern California (KPNC) with incident CIN2+ between July 2008 and June 2009. The primary outcome was the proportions of cytologic diagnoses and hrHPV co-test results preceding a diagnosis of CIN2+. Cervical cytology and hrHPV testing results were abstracted from electronic medical records. Of 1283 CIN2+ cases among adult women, 880 (68.5%) were among women aged 30 years and older and 145/880 (16.5%, 95% CI 14.1-19.1) had only normal cytology during the 12 months prior to diagnosis. Furthermore, 133/880 (15.1%, 95% 12.9-17.7) were preceded by only normal cytology and persistent hrHPV infection (at least 2 positive hrHPV tests) during the 6-36 months preceding CIN2+ diagnosis. Incident CIN2+ is frequently preceded by normal cytology and persistent hrHPV infection among women aged 30 years and older; screening strategies that employ HPV testing and cytology may improve the detection of CIN2+ compared with cytology alone.