Prevailing state and institutional ideologies regarding race/ethnicity, gender, and sexuality help to shape, and are influenced by, research priorities. Research ethics committees perform a gatekeeper role in this process. In this commentary, we describe efforts to obtain approval from the ethics committee of a large medical institution for research into the treatment of homosexual persons by health professionals in the South African military during the apartheid era. The committee questioned the "scientific validity" of the study, viewing it as having a "political" rather than a "scientific" purpose. They objected to the framing of the research topic within a human rights discourse and appeared to be concerned that the research might lead to action against health professionals who committed human rights abuses against lesbians and gay men during apartheid. The process illustrates the ways in which heterosexism, and concerns to protect the practice of health professionals from scrutiny, may influence the decisions of ethics committees. Ethics that exclude research on lesbian and gay health cannot be in the public interest. Ethics committees must be challenged to examine the ways in which institutionalized ideologies influence their decision making.