In China, men who have sex with men (MSM) are at increasingly high risk for HIV. However, prevention efforts targeting this population may be hindered because of the stigma associated with homosexuality in traditional Chinese culture. We conducted qualitative interviews with 30 MSM in Shanghai to better understand the types and sources of stigma and discrimination and how MSM respond to them. The stigma associated with homosexuality can be traced back to four culturally based factors: social status and relationships, the value of family, perceptions of immorality and abnormality, and gender stereotypes of masculinity. In particular, the centrality of the family and the importance of maintaining key relationships caused stress and anxiety, contributing to more frequent encounters with felt stigma. In response, MSM often evaded the scrutiny of family members through various tactics, even prompting some to leave their rural homes. Implications of these findings on HIV/AIDS prevention are discussed.