INTRODUCTION: General practitioners (GPs) can improve HIV and sexually transmitted infection (STI) screening, vaccination and wellbeing among gay, bisexual and other men who have sex with men (GBM) if they are aware of a patient?s sexual orientation. AIM: To estimate GP awareness of their GBM patients' sexual orientation and examine whether HIV and STI screening was associated with this. METHODS: We analysed anonymous, self-completed data from 3168 GBM who participated in the community-based Gay Auckland Periodic Sex Survey (GAPSS) and internet-based Gay men's Online Sex Survey (GOSS) in 2014. Participants were asked if their usual GP was aware of their sexual orientation or that they had sex with men. RESULTS: Half (50.5%) believed their usual GP was aware of their sexual orientation/behaviour, 17.0% were unsure, and 32.6% believed he/she was unaware. In multivariate analysis, GP awareness was significantly lower if the respondent was younger, Asian or an 'Other' ethnicity, bisexual-identified, had never had anal intercourse or had first done so very recently or later in life, and had fewer recent male sexual partners. GBM whose GP was aware of their sexual orientation were more likely to have ever had an HIV test (91.5% vs 57.9%; p<0.001), specific STI tests (91.7% vs 68.9%; p<0.001), and were twice as likely to have had an STI diagnosed. DISCUSSION: Lack of sexual orientation disclosure is resulting in missed opportunities to reduce health inequalities for GBM. More proactive, inclusive and safe environments surrounding the care of sexual orientation minorities are needed in general practice to encourage disclosure. KEYWORDS: Culturally competent care; general practice; HIV; HPV; sexual health; sexual orientation