Eighteen out of 19 women who were clinically well but infected by HIV showed abnormalities of the lower genital tract. Seven patients had intraepithelial neoplasia, histologically verified in five, involving the cervix in four, the vulva in three and the perineum in one. Lesions (clinical and/or subclinical) compatible with human papillomavirus (HPV) infection were identified in these women, as well as in 10 out of the other 11 women infected with HIV. Disease at more than one site was detected in half of the patients and would have remained covert in more than half, had colposcopy not been undertaken. Women with HIV infection are at high risk of harbouring HPV and of developing lower genital tract neoplasia.