Granulomatosis with polyangiitis (GPA) is a primary, systemic small vessel vasculitis. The respiratory tract is typically involved in the course of the disease. Abnormalities on the chest radiograph are noted in more than 70% patients at some point during their disease history. In some clinical situations it is difficult to distinguish whether symptoms result from the underlying disease or are a symptom of infection. In these clinical situations, chest computed tomography (CT) can be very useful. We present a patient with GPA localized mainly in the respiratory tract with sudden deterioration of the general state and new abnormalities revealed in the CT of the chest.