Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare disease and has occasionally been described after vaccination, especially against viral agents. We present a case of a patient who presents with the classic pentad of TTP a few days after receiving the first dose of the mRNA Pfizer COVID‐19 vaccine. To our knowledge, this is the second report of a de novo TTP following mRNA Pfizer COVID‐19 vaccination.