We assessed trends in HIV testing outcomes during a period of clinic-based initiatives introduced to increase HIV testing among gay and bisexual men (GBM) attending sexual health clinics (SHCs) in New South Wales (NSW). A cohort of 25,487 HIV-negative GBM attending 32 SHCs in NSW (2009-2015) was classified into six sub-groups each year based on client-type (new/existing), risk-status (low/high-risk), and any recent HIV testing. Poisson regression methods were used to assess HIV testing outcomes in sub-groups of GBM. HIV testing outcomes and the sub-groups with greatest statistically significant annual increases were: individuals attending (26% in high-risk existing clients with recent testing); testing uptake (4% in low-risk existing clients with no recent testing); testing frequency (6% in low-risk existing clients with no recent testing and 5% in high-risk existing clients with recent testing); and total tests (31% in high-risk existing clients with recent testing). High-risk existing clients with recent testing had a 13% annual increase in the proportional contribution to total tests. Our findings show improved targeting of testing to high-risk GBM at NSW SHCs. The clinic-based initiatives should be considered for translation to other similar settings.