OBJECTIVE:To demonstrate that women treated for PID constitute a population with a specially high incidence of cervical intraepithelial neoplasia (CIN) and who should be screened for CIN. POPULATIONS AND METHODS:Retrospective, non-comparative study of 260 patients treated for PID in the Gynecology-Obstetrics Department of Hôtel-Dieu hospital in Rennes (France) from December 1st, 1989 to May 31st, 1996. CIN screening was performed by smear tests and colposcopy. RESULTS:Cervical lesions were detected in 39 patients (15%): five CIN 3 (including one early-stage microinvasion), twelve CIN 2 and 22 CIN 1 and/or condylomas, i.e., 6.5% high grade and 8.5% low grade lesions. Colposcopy in this case proved to be more effective than smears for screening. DISCUSSION:According to epidemiological studies, sexual behavior is a major risk factor of CIN, due to the role played by sexually transmissible human papillomavirus in their pathogenesis. Because the main risk factor of PID is sexual activity, it is likely that CIN are more frequent in women with PID. Our study clearly established that fact because the prevalence of CIN in the general population is only 0.5 to 4% according to literature reports. CONCLUSION:We are in favor of CIN screening in women treated for PID, and in our view colposcopy is the preferred method.