Objectives The immunogenicity and safety of the Pfizer-BioNTech BNT162b2 mRNA vaccine in people living with HIV-1 (PLWH) are unknown. We thus aimed to assess the immunogenicity and safety of this vaccine in PLWH. Methods In this prospective open study, we enrolled 143 PLWH, aged ≥18 years, who attended our clinic and 261 immunocompetent health care workers (HCWs). SARS-CoV-2 receptor binding domain (RBD) IgG and neutralizing antibodies were measured. Adverse events, viral load and CD4 cell counts were monitored. Results At a median of 18 days (IQR 14-21) after the second dose, anti-RBD IgG was positive in 139/141 (98%) PLWH. Among HCWs, 258/261 (98.9%) developed anti-RBD IgG at a median of 26 (IQR 24-27) days after the second dose. Following the second dose, immune sera neutralized SARS-CoV-2 pseudo-virus in 97% and 98% of PLWH and HCW, respectively. Adverse events were reported in 60% of PLWH, mainly pain at the injection site, fatigue, and headache. AIDS-related adverse events were not reported. HIV viral load increased in 3/143 (2%) patients from < 40 copies/mL to ≤ 100 copies/mL. CD4+ T cell count decreased from a geometric mean of 700 (95% CI 648–757) cells per μL to 633.8 (95% CI 588–683) cells per μL (P<0.01). Conclusions BNT162b2 mRNA vaccine appears immunogenic and safe in PLWH who are on ART with unsuppressed CD4 count and suppressed viral load.