Ruili is a small border town between China and Myanmar where drugs and commercial sex are common, and rates of sexually transmitted diseases (STDs) including HIV, are high. A qualitative study was carried out on 89 commercial sex workers there in 2001 to understand more about their HIV awareness, medical-seeking behaviors and needs. We found that the sex workers were young and the turnover rates were high. Contrary to common belief, many came from nearby villages or cities, but were probably reluctant to participate in organized activities. Their medical knowledge was very limited, often acquired from peers and self-medication was common. The contraception they used was inappropriate and screening for cervical cancer was nonexistent. They were very stigma conscious. Condoms were purchased in small quantities when required and used only if the clients were agreeable. These findings have strong implications for the future planning of services and HIV/STD prevention.