Chengdu is a major city in southwest China with a huge MSM population. Surveillance data indicated that HIV prevalence among MSM in Chengdu surged from 0.64% in 2003 to 6.58% in 2006, and consistent condom use when having anal intercourse remained at about 40% after a four-year intervention effort was initiated. A combined qualitative study and questionnaire survey using a snowball sampling method was conducted among MSM in Chengdu in 2006/2007. Forty-three MSM participated in focus group discussions and in-depth individual interviews. Stigma and social pressure for MSM were mainly reported to be from one's family to get married and have children to protect the family's reputation and lineage. Few participants reported stigma and discrimination from friends, colleagues, or society. Fear of being ostracized for their sexual orientation does exist, and prevents MSM from taking part in HIV/AIDS prevention programs. Fear of stigma and discrimination of HIV infection from inside the MSM community was identified as one of the major reasons for MSM refusing HIV testing or treatment. A total of 538 MSM were recruited to the study. HIV, HSV-2, and syphilis were detected among 9.1%, 24.7%, and 28.1%, respectively. Consistent condom use was low, and varied by types of sexual partners. Knowledge of correct condom use was low (23.4%). Money boys were almost five-fold more likely to be infected with HIV. A history of HSV and/or syphilis increased the risk of HIV infection over four-fold. Other risk factors included not knowing how to use condoms properly and having lived in Chengdu for more than five years. HIV/AIDS programs among MSM must be sensitive to stigma, both from outside and inside the MSM community. Confidentiality and follow-up services for those testing HIV-positive are key to HIV intervention programs to persuade more to be tested. To prevent HIV/STDs, campaigns promoting and educating about condom use are urgently needed. Certain subpopulations, such as those infected with STDs or who engage in commercial sex, require greater effort. To promote HIV VCT among MSM, more information about where to be tested and how to cope with positive results should be disseminated throughout the population.