Background: Cervical cancer is one of the most preventable cancers, not only presence of effective HPV vaccination but also simple and robust screening methods such as Pap test. Nevertheless, there were some women at risk whom were unable to access screening cause of incarceration. Hence, in 2018, together with Songkhla Woman Correctional Institute, we launched a cancer screening campaign including clinical breast exam, mobile mammography and Pap test. This is the first report of cervical cancer screening result demonstrated the essential of cervical cancer screening in these disadvantaged women. Methods: Due to the regulation of the jail, we had to limited bring-in tools, allowed staffs and operating-time, therefore we used a pre-screening questionnaire, included 5 items: HIV infection, number of partner, parity, age at first sexual intercourse and number of term baby and each of them scored as 2 for “high-risk” and 1 for “low-risk”, total score ranged from 5 to 10. We ranked and chose the volunteer participants, who have HIV infection and/or with highest risk score, to undergo Pap test. Results: Of the 1328 questionnaire responders, Their mean risk score was 7.3 (SD= 1.3). HIV infected participants number were 34 (2.5%). Of the 200 screened-participants, None of them had ever received HPV vaccination before, and all participant did not have Pap test since imprisonment. (mean 53.8 m, range 13-236 m, SD 36.7). Their score ranged between 8 to 10, 42.5% of them had score level 8, 54.5% had score level 9 and 3% had score level 10. Mean age was 37.7 years. 10 (5%) of them had abnormal Pap test; 1 of them showed ASC-US, 1 was LSIL, 1 was ASC-H, 5 of them showed HSIL and 2 of them showed squamous cell carcinoma and small round cell carcinoma. Final histopathological test resulted in 6 of cervical intraepithelial neoplasia (CIN) I, metaplasia and cervicitis, 3 were diagnose CIN III and 1 diagnosed microinvasive carcinoma. Incidence of cervical cancer was higher than normal population in this region. (0.5% vs 0.02%). Conclusions: Incarcerated women were at high risk of cervical cancer compared to normal population. Unfortunately, in many places, they were unconditionally inaccessible to the cervical cancer preventive healthcare system for years. Social should increase awareness to decrease this health disparity.