Purpose: Sexual orientation affects individuals' health histories and is fundamental to providers' understanding of patients as a whole. Gay, bisexual, and other men who have sex with men (GB-MSM) are vulnerable to certain health conditions, including HIV. The aim of this exploratory analysis was to examine factors associated with sexual orientation disclosure and communication with providers about GB-MSM health issues and to discuss implications. Methods: We conducted a cross-sectional internet survey of GB-MSM (n = 202) in London-Middlesex, Ontario, Canada; analyses were limited to those with a regular primary care provider (n = 173). Blockwise regression models explored demographic, psychosocial, and healthcare-related factors associated with sexual orientation disclosure and physician-patient communication about GB-MSM-related health. Results: Just over seventy-one percent (71.1%) of participants reported that their primary care provider (PCP) knew their sexual orientation, and 44.5% had talked to them about GB-MSM health. Overt negative comments or being refused care based on sexual orientation occurred infrequently, although 26.6% reported their provider had assumed they were heterosexual. Being married to or living common-law with another man, more frequent experiences of homosexual prejudice, and higher quality assessment of provider's communication skills were associated with the PCP knowing respondents' sexual orientation. Greater internalized homonegativity was associated with not talking to a PCP about GB-MSM-related health issues. More frequent experiences of homosexual prejudice, higher assessment of provider communication, and having prior negative experiences with a PCP were significantly associated with talking to a PCP about GB-MSM health. Conclusion: The majority of our sample disclosed their sexual orientation; however, not all patients voluntarily disclose. Medical training and education in Canada, where specific rights protections exist for sexual orientation minority populations, should emphasize awareness of essential patient health information. Training should include information about GB-MSM health and building a foundation on how to speak with GB-MSM patients nonjudgmentally.