There are 4 possible explanations, which are not mutually exclusive: 1 bias in assessment of risk behaviors, 2 increased prevalence of HIV among sexual contacts, 3 increased infectiousness among sexual partners, and 4 increased physiological susceptibility to HIV. By exploring these possibilities more deeply, we can increase our understanding of the apparent disparity between behavioral risks and outcomes while at the same time improving the design and implementation of prevention programs that address the specific needs of BMSM. Methodological problems that may lead to underreporting of risk behaviors may also explain why behavioral messages fail to translate into safer sex among BMSM: Measures, surveys, and instruments may be culturally inappropriate for BMSM; interviewers may not be race- and gender-concordant with or may not be properly trained to interview BMSM; instruments may use language or terminology that does not resonate with BMSM; research settings may not be comfortable environments for open discussion with and responses by BMSM. Meanwhile, BMSM research participants may 1 be unwilling to use certain sexual orientation labels on surveys for fear of discrimination, 2 distrust or fear researchers, 3 fear that confidential information about their sexual behavior will be disclosed, or 4 report what they think researchers want to hear. To solve these problems, researchers must conduct more qualitative research with BMSM in environments that provide a more comfortable atmosphere in which to talk openly about sensitive sexual issues.