Context and Objective: On May 24, 2019, Taiwan becomes the first country in Asia to legalize same sex marriage. However, many supporters felt disappointed by the referendum on marriage equality that took place on November 24, 2018. Marriage equality was discussed in Taiwan before the referendum, which entailed many public hearings and debates. There were alliances opposing same sex marriage (referred to as "anti-same sex marriage groups"), as well as alliance that supported same sex marriage. During these debates, anti-same-sex marriage groups highlighted HIV/AIDS issues as justification for opposing same-sex marriage with arguments that included, "most people infected with HIV are gay", "gay sex among men is the primary factor in HIV transmission", " legalizing same sex marriage will cause the spread of HIV/AIDS epidemic", "Taiwan will become an HIV/AIDS island", "The cost of HIV/AIDS treatment will consume medical resources," and "Taiwan should not provide health care benefits to those who got HIV/AIDS." Internet and social media outlets have promoted numerous negative messages about HIV/AIDS, and the anti-same-sex marriage group still uses "HIV/AIDS" as a reason to repeatedly attack the gay community. The present research aims to understand the psychological impact of negative HIV/AIDS propaganda on gay men living with HIV/AIDS in Taiwan and how they coped during the marriage equality referendum. Methods: We first collected articles, pictures, videos, and news about anti-same- sex marriage justification for discrimination against HIV/AIDS from websites, social media, and mobile APP. We then recruited focus group participants through AIDS service for non-governmental organizations. On the day of the focus group in April 2019, we made a brief presentation on relevant negative propaganda before conducting the 2.5 hours focus group. We then conducted a qualitative content analysis after the verbatim transcript was created. The average age of the eight interviewees was 38.75, and the average years of HIV infection was 11 years. All participants were taking HAART (highly active antiretroviral therapy). The interviewees all stated that they had received negative propaganda messages about AIDS on social media during the marriage equality referendum promotion period. Results: (1) Respondents will make fun of the content of the propaganda, or feel bored and angry. In response, they will avoid, be objective and calm, or take the initiative to educate those around them. (2) Ways to respond to negative propaganda messages: somebody would avoid, disregarded, and simply ignore it; somebody would aim and calm, or somebody would actively educate other people around them. (3) There are three dilemmas: (a) They do not want to have conversations with anti-same sex marriage group that distribute the AIDS- stigma messages and instead look forward to clarification by officials (Taiwan Centers for Disease Control) and other powerful non-government organization; (b) Interviewees do not want to hurt other vulnerable groups during the process that messages are clarified; (c) They are worried about affecting the public's perception of the gay community or being separated from the gay community. (4) For HIV/AIDS anti-discrimination advocacy recommendations, the effectiveness of HAART treatment should be strengthened, the official classification of HIV/AIDS statistics should be revised, and vulnerable groups that are friendly to HIV/AIDS should be invited to form alliances. (5) In particular, some of their family members began to discuss homosexuality issues, making the interviewee feel accepted, but it was still not easy to show up as a PLWHA. Discussion and Conclusion: Based on the research results, this study suggests: (1) Self-stigma is deeply rooted in PLWHA; (2) Public anti- discrimination education for HIV/AIDS needs to be promoted as soon as possible, especially on HAART treatment effects. Gay men with HIV/AIDS are discriminated against HIV/AIDS in the marriage equality referendum, and they are caught in a situation that includes both self-stigma and external discrimination.