Men are primarily responsible for the transmission of HIV because of their participation in risk-taking activities such as unsafe sex (i.e. homosexual and/or heterosexual) and drug injections. Men, particularly men having sex with other males, were identified by the DOH-HIV Serologic Surveillance as one of the subpopulations with the highest risk of acquiring HIV. This can be attributed to their behavior towards safe sex, masculinity and their partner. The main objective of this study was to conduct a formative and qualitative assessment on HIV and AIDS among MSM (men who have sex with other males) in the Philippines by identifying the constructions of their sexual identities and their sexual behaviors and risks using the following themes: social mobility; and, health seeking behaviors. Multiple methods have been utilized in this study such as environmental scoping, key informant interviews and focus group discussion sessions in four selected sites in the Philippines. A Delphi technique was also used to solicit opinion of experts in the field of medical, allied medical and social sciences. Results of this study showed that MSM is a vulnerable and susceptible sub-population group to STI, HIV and AIDS due to the complexities of understanding their own sexualities, the gap between their actual and ideal health seeking behaviors and various sexual experiences that brought about the dynamics of sexual proclivities. The study recommends a strong programmatic design for intervention among MSM to become positive agents of change in STI, HIV and AIDS education.