Only few cases have been reported of necrotizing glomerulonephritis (GN) associated with myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) in patients with RA.<h4>Case presentation</h4>We report a patient with RA who developed a necrotizing GN associated with ANCA-MPO, treated with rituximab (RTX). The gene discussed is MPO; the disease is rheumatoid arthritis.