Gay, bisexual and other men who have sex with men (GBMSM) experience greater health disparities, and concern about other health conditions may decrease engagement in HIV prevention. This study assessed perceived threat and impact of HIV relative to other health concerns among GBMSM. Data were from a national online survey of GBMSM conducted between August and September 2015. Participants ranked concern about contracting HIV and impact of HIV on their health compared with other health conditions. The association of HIV threat and impact with recent condomless anal sex (CAS) and HIV testing were assessed using regression models. Among 466 participants, threat and impact of HIV were ranked lower compared to cancer, Alzheimer's and heart disease. Concern about getting HIV was associated with greater odds of recent HIV testing (adjOR 1.1, 95%CI 1.02-1.18) and lower CAS (adjOR 0.86, 95%CI 0.78-0.94). Among GBMSM, other health conditions may be perceived as a greater threat and higher impact on health compared with HIV. Integrating complex health care concerns with HIV prevention strategies may increase engagement in prevention.