The purpose of this study was to see if an outreach model could be a feasible option for early detections of preinvasive cervical cancer in women with double identities of female sex workers (FSW) and illegal migrant workers in Hong Kong who most needed cervical screening but were often deprived of such a service. High turnover rates, acceptability, and compliance for follow-ups could potentially render such a clinical model unsuccessful. A total of 245 FSW were screened at the outreach clinic from January 2004 to December 2005, which was set up in a nongovernmental organization in a red light district. A questionnaire regarding their lifestyles and demographic details was used before a gynecological history, Papanicolaou (PAP) smear, and other health checkup were conducted. Chi-square test and multinomial logistic regression were used to analyze the results. Of 235 women tests, 9.8% of them had CIN I-III, and places of origin were found to be important risk factors for abnormal PAP smears. The nonlocal workers were significantly more likely to have abnormal PAP smears (chi(2)= 10.55, P= 0.04). Among the women, 88.1% of them who had the tests returned for follow-up with poorer compliance among those with an abnormal result. We conclude that an outreach well-women clinic seems to be an acceptable option for these women and an effective way for the early detection of cervical cancer.