Background: Single-tablet regimen (STR) provides a convenient once-daily regimen for the prevention of human immunodeficiency virus (HIV) infection. Here, we investigated the safety and tolerability of coformulated bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) as a three-drug, STR for post-exposure prophylaxis (PEP) in Chinese individuals. Methods: This was a prospective, open-label, single-arm trial conducted in a sexually transmitted diseases and acquired immunodeficiency syndrome clinic of a tertiary hospital in Beijing, China. Adults requiring PEP were prescribed BIC/FTC/TAF one pill once a day for 28 days. Clinical and laboratory data were collected and analyzed at baseline, weeks 2, 4, 8, 12, and 24. Results: Of 112 participants enrolled in the study, 109 (97.3%) were male and the mean age was 30 ± 8 years. PEP completion was 96.4% (95% confidence interval: 91.1–99.0%). Two participants stopped PEP after 2 days because the source partner was identified as HIV uninfected. One participant was excluded due to hepatitis B virus infection according to the exclusion criteria. One discontinued due to the participant's decision. No participant acquired HIV through week 24. Adherence was 98.9% (standard deviation [SD]: 3.3%) by self-reporting and 98.5% (SD: 3.5%) by pill count. Only five participants experienced mild clinical adverse events attributed to the study drug (including headache, diarrhea, and nausea) and four participants had elevated serum creatinine (grade 1). Conclusions: A once daily, STR of BIC/FTC/TAF used as PEP was safe and well-tolerated with a high rate of completion and adherence in Chinese. BIC/FTC/TAF may be a good option for PEP. Trial Registration: ChiCTR.org.cn, ChiCTR2100048080

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