GPA is a systemic, necrotizing, small-vessel vasculitis associated with circulating anti-neutrophil cytoplasmic autoantibodies (ANCA), and so-called ANCA-associated vasculitis (AAV). A white woman in her early thirties was sent to the hospital because of hemoptysis, dyspnea, fever, cough, general fatigue, swollen joints. Chest radiography on hospital admission detected diffuse small nodules in both lungs. Laboratory tests: white blood cells 13.9…16.7…18.2 × 109/L, hemoglobin 91…80…110g/L, hematocrit 30…25..35%, erythrocytes 3.7…3.1…4.2 × 1012/L, platelet count 4.45…5.5…5.7 × 109/L, sedimentation rate 72…60…45mm/h per the first hour, C-reactive protein 111…80…35mg/L, D-dimer 4100…3500…1250 ng/ml. Biochemistry analysis: kidney function tests (blood urea nitrogen 10.4…7.4…5.6 mmol/L, creatinine 110…95…87 μmol/L, liver tests normal, albumin 28g/L, total protein 58 g/l. Urinalysis: mild proteinuria (+), 16–18 red blood cells, epithelial cells (++), 24-hour proteinuria 0,52g/L. Gas analyses: partial oxygen pressure 7.6…8.9…9.3 kPa, the partial pressure of carbon dioxide 3.7…4.2…4.6 kPa, oxygen saturation 90…93…95%. She was febrile 38.5°C, heart rate 122 beats/minute, swollen ankles, pale skin, conjunctival hyperemia, coagulated blood in both nostrils. Lung auscultation sounds normal. Lung CT scan detected diffuse, bilateral, small nodules, some of them with areas of cavitation and pseudo-cavitation. Autoimmune antibody tests: positive c-ANCA 95U/ml, negative p-ANCA, negative RF 158IU/ml, positive antiproteinase - 3 900 U/ml. Renal ultrasonography normal. IL-6 serum level normal 5 pg/ml, also C3 level 1.2 g/L and C4 level 0.3 g/L. Lung ultrasonography: bilateral, irregular, subpleural, hypoechogenic changes, with different size and central necrosis. Tracheobronchial mucosa was vulnerable, inflamed and edematous, bronchial lavage negative for malignancy and infection. Bronchial biopsy detected necrotic granulomas with multinucleated giant and inflammatory cells confirming the diagnosis of PGA. Cyclophosphamide combined with corticosteroids was given four months until the time of remission. The corticosteroid dose was slowly reduced and cyclophosphamide was switched to azathioprine to maintain remission. The treatment duration of the maintenance immunosuppressive medication after 10 months follow up is still ongoing with continuous monitoring of side effects.