Vaccines are today considered one of the most effective means against the Sars-CoV-2 pandemic. The BNT162b2 vaccine by Pfizer/BioNTech has been massively administered throughout the globe; since its approval, a wide spectrum of cutaneous reactions has been reported. Here we report the case of a 52-year-old Caucasian male who presented with an acute febrile eruption that arose 72 h after the first dose of the BNT162b2 vaccine. The clinicopathological findings were consistent with Sweet’s syndrome. The short latency time suggested a possible role of the vaccine in triggering Sweet’s syndrome in this case.