PROBLEM: Mucosal T cells are the most likely direct effectors in host anti-human papillomavirus adaptive immunity and regression of cervical intraepithelial neoplasia (CIN) lesions. There are no studies addressing intraepithelial lymphocytes (IELs) in CIN lesions. METHOD OF STUDY: Cervical lymphocytes were collected using cytobrushes from patients with CIN and analyzed by FACS analysis. Comparisons were made between populations of cervical T cells in CIN regressors and non-regressors. RESULTS: A median of 74% of cervical lymphocytes were CD3(+) T cells. Populations of integrin αEβ7(+) IEL in CIN lesions varied markedly among patients (6-57%). Approximately half of integrin β7(+) T cells were CD45RA-negative memory T cells. The number of integrin αEβ7(+) cells among cervical T cells was significantly higher in CIN regressors when compared to non-regressors. CONCLUSION: Higher cervical IEL numbers are associated with spontaneous regression of CIN. Accumulation of cervical integrin αEβ7(+) IEL may be necessary for local adaptive effector functions.