Introduction: Cases of acute myocarditis have been after administration of the BNT162b2 and Ad26.COV2.S vaccine.Objective: Describe another possible mechanism of myocarditis after COVID-19 vaccination.Case presentation: We describe the clinical case of a 72-year-old female with pleuritic chest pain one week after the third of the BNT162b2 mRNA vaccine. Serological tests for cardiotropic pathogens were negative, and autoimmunity screening was positive with anti-nuclear antibody (ANA) in 1:160 dilu-tion, Anti-double-stranded DNA (anti-dsDNA), and anti-histone antibodies. 18F-fluoro-deoxy-glucose (FDG) positron emission tomography/computed tomography (PET/CT) showed a focal myocardial and pericardial inflammatory process in the cardiac apex.Results and discussion: Systemic lupus erythematosus (SLE) diagnosis was made with myocardial affec-tion. As far as we know, this is the first report of a case of lupus myocarditis after the COVID-19 vaccine.Conclusion: Given the pathogenic rationales, the association between SLE and myocarditis should be considered.(c) 2022 Elsevier Espana, S.L.U. and Sociedad Espanola de Reumatologi acute accent a y Colegio Mexicano de Reumatologi acute accent a. All rights reserved.