Context.-Women who have been treated for high-grade cervical or vaginal intraepithelial neoplasia (CIN or VAIN) or invasive carcinoma are at risk for recurrent/persistent disease and require long-term monitoring. The role of human papillomavirus (HPV) testing in this setting is unclear.Objective.-To evaluate the clinical performance of the Hybrid Capture 2 (HC2) HPV test for recurrent/residual high-grade CIN or VAIN in patients with a posttherapy abnormal squamous cells of undetermined significance (ASC-US) Papanicolaou test result.Design.-We reviewed the follow-up data on 100 patients who had an ASC-US Papanicolaou test and HC2 HPV results after treatment for high-grade CIN/VAIN or carcinoma. Human papillomavirus genotyping was performed for women with a negative HC2 result whose follow-up biopsy revealed CIN/VAIN 2þ.Results.-The patients' mean age was 47 years. The HC2 test result was positive in 33% of the patients. Follow-up biopsy was available for 17 of these patients (52%) and for 25 of the 67 patients (37%) with a negative HC2 result. A total of 5 of the patients (29%) with a positive HC2 result and 2 of the patients (8%) with a negative HC2 result had CIN/VAIN 3 on follow-up biopsy, a statistically insignificant difference (P ¼ .10). Human papillomavirus 16/18 genotypes were detected in the CIN/VAIN 2þ lesions of 5 patients with a negative HC2 result.Conclusions.-HC2 yielded a false-negative rate of 8% for CIN 3. HC2 testing therefore may not be sufficient for triage of patients with an ASC-US Papanicolaou test result. Patients with ASC-US during long-term posttherapy followup need close monitoring, with colposcopic evaluation if clinically indicated.