Journal of the Medical Association of Thailand Vol 93, No 3:MARCH 2010 (SUPPL.3) 0125-2208 93 3 2010 Mar Health Behaviors in the Development and Maintenance Process of Homosexual Identity 6 EN Thaidharmarose Patthum Pattapong Kessomboon Narumon Sinsuphan Amornrat Ratanasiri Original Article To explore the health behaviors related to the development and maintenance process of men who have sex withmen. This was a qualitative study. The study population was MSM in Mukdahan province. The subjectswere recruited gradually, by snowball sampling, until the required data were saturated. In-depth interviews and participantobservations were performed over a period of 17 months. A triangulation technique was applied to check reliability of thedata. Data were analyzed by content analysis and compared with the Troiden’s stages of development and maintenanceprocess of homosexual identity. Eleven Thai MSM were recruited and followed up. Health behaviors of them were different according to the stagesof development and maintenance process regarding Troiden’s theory. Physical, psychological, social and sexual aspects ofhealth behaviors were identified in various stages. It was found that many factors affect health behaviors of MSM. Theseinclude health promoting and undermining factors. Health behaviors of MSM varied in each stage of development and maintenance of homosexual identity. Healthpromotion campaigns and policies for MSM should be designed accordingly. Health behavior Men who have sex with men MSM Development and maintenance process Homosexual identity