MPO and influenza: <h4>Background</h4>Although influenza vaccines are generally safe and effective, a variety of autoimmune phenomena have been reported after vaccination over the past years, such as Guillain-Barre syndrome, rheumatoid arthritis, pemphigus vulgaris, psoriasis, giant cell arteritis and anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV).<h4>Case report</h4>We describe the case of a 67-year old man who presented with a myeloperoxidase-ANCA associated vasculitis with renal involvement and mononeuritis multiplex after seasonal influenza vaccination.