We aimed to determine the prevalence of HPV-16/18 antibodies in Korean women with high-grade cervical intraepithelial neoplasia (CIN) and cervical cancer. We conducted the hospital-based case-control study at the university hospital between 2003 and 2006. Cases were 130 high-grade CIN and 43 cervical cancer patients and the control group was 106 women showing normal cervical cytology. Enzyme-linked immunosorbent assays were performed for HPV-16/18 L1 virus-like particles (VLPs) as an antigen. Seropositivity for HPV-16 VLP and HPV-18 VLP was found in 67.4% and 30.2% of cancer patients and 59.2% and 20.0% of high-grade CIN patients, respectively. Seropositivity for HPV-16 with high-grade CIN (OR 6.91; 95% CI 3.74-12.76) and cervical cancer (OR 8.99; 95% CI 3.88-20.84) presented significant associations, as did seropositivity for HPV-18 (high-grade CIN: OR 3.64; 95% CI 1.67-7.95, cervical cancer: OR 6.82; 95% CI 2.52-18.45). Patients with both HPV-16 and 18 seropositivity were 9.38 times (95% CI 2.98-29.51) more likely to have high-grade CIN and 17.05 times (95% CI 4.55-63.87) more likely to have cancer. Both HPV 16 and 18 L1 VLP serology is the clear disease predictors of presence of high-grade CIN and cervical cancer.