Abstract: Objective To examine the status of knowledge,attitude and practice about human immunodeficiency virus(HIV) and acquired immunodeficiency syndromes(AIDS) among the men who have sex with men(MSM) in Lhasa municipality of Tibet Autonomous Region and to provide evidences for developing prevention strategy and health education program in the MSM.Methods Using cross-sectional design,we recruited MSM living in Lhasa for two weeks or more for a survey with self-administered questionnaire and face-to-face interview at a gay bar from 2012 through 2013.We adopted SPSS 19.0 in data analyses.Results A total of 124 valid questionnaires were collected.The average age of the respondents was 28.8±7.0 years.Of the respondents,57%(71/124) had their first sexual activity with a female partner and only 23.4%(29/124) used condom in their most recent anal sex activity.The AIDS awareness rate was above 50% for all the respondents;7.3%(9/124) of the respondents reported history of sexually transmitted diseases and 87.9%(109/124) expressed the intention to marry a female.Conclusion Unsafe sexual behavior is common among MSM in Lhasa city,suggesting sentinel surveillance on AIDS should be established among the MSM.