OBJECTIVE: Scale-up of human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP) has raised concerns regarding its impact on clinic capacity and access to HIV testing. We describe enrolment in PrEPX, a large PrEP implementation study in Victoria, Australia, and the impact of PrEP uptake and maintenance on existing health services. METHODS: We describe enrolment between July 26, 2016, and March 31, 2018, and trends in HIV testing among PrEPX participating and nonparticipating gay and bisexual and other men who have sex with men (GBM) at 5 study clinics participating in a sentinel surveillance system (ACCESS). We evaluated HIV and STI testing trends using segmented linear regression across the prestudy (January 2015 to June 2016) and PrEPX study (July 2016 to March 2018) periods. FINDINGS: There were 2,049 individuals who registered interest in study participation: 72% enrolled into the study. Study clinics enrolled participants rapidly; of 4265 people enrolled in PrEPX (98% GBM), 1000 enrolled by week 3, 88% (n = 876) of whom enrolled at ACCESS sites.Prestudy period HIV testing rates were increasing at all ACCESS sites. In the month PrEPX commenced, there was an additional 247 HIV tests among PrEPX participants (P < 0.01) and no significant change among non-PrEPX GBM (P = 0.72). Across the study period, HIV testing increased by 7.2 (P < 0.01) and 8.9 (P < 0.01) tests/month among PrEPX participants and non-PrEPX GBM, respectively. The HIV testing increased among non-PrEPX GBM at sexual health clinics (18.8 tests/month, P < 0.01) and primary care clinics (7.9 tests/month, P < 0.01). Similar trends were observed across testing for all measured STIs. CONCLUSIONS: Rapid PrEP scale-up is possible without a reduction in HIV testing among GBM not using PrEP.