Background Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis, is a systemic inflammatory process predominantly affecting upper and lower respiratory tract and kidneys. Valvular heart disease is a rare manifestation of GPA.Case summary We report two cases of acute valvular heart disease mimicking acute endocarditis caused by GPA. Both patients were middle-aged females with acute aortic valve regurgitation suggestive of possible infective endocarditis. In their recent medical history, atypical otitis and sinusitis were noted. The first patient was admitted with heart failure and the second patient because of persisting fever. Echocardiogram revealed severe aortic regurgitation with an additional structure on t...