Anti-glomerular basement membrane (anti-GBM) disease is an acute and life-threatening systemic autoimmune disorder. The coexistence of circulating anti-neutrophil cytoplasmic antibodies (ANCA) and anti-GBM disease, the so-called double-positive disease (DPD), is exceptionally rare. We report a unique case of DPD manifesting as pulmonary-renal syndrome (PRS) in a 46-year-old woman who first presented with clinical and radiological suspicion of pneumonia. Chest computed tomography scan later revealed bilateral alveolar hemorrhage. Kidney biopsy showed necrotizing crescentic (100% glomeruli) glomerulonephritis. On immunofluorescence microscopy, glomeruli were global linear positive for IgG, confirming anti-GBM disease. Double positivity was detected for circulating anti-myeloperoxidase ANCA (p-ANCA) and anti-GBM antibodies. Acute renal failure evolved rapidly. Therapeutic plasma exchange (TPE) and hemodialysis (HD) were initiated early in combination with intravenous pulse corticosteroid therapy followed by oral methylpred-nisolone and cyclophosphamide. Pulmonary hemorrhage resolved, but renal function could not be preserved. The patient remains HD dependent. This case report highlights that pulmonary symptomatology may be the leading clinical presentation of PRS, with initially normal renal function at DPD onset. Early recognition and diagnosis are therefore crucial to timely clinical intervention. The role of prompt kidney biopsy and initiation of TPE and HD in PRS must not be underestimated. Key words: anti-glomerular basement membrane (anti-GBM) disease, Goodpasture's syndrome, p-AN-CA (anti-neutrophil cytoplasmic antibodies), pulmonary-renal syndrome, rapidly progressive glomerulonephritis with pulmonary hemorrhage Bolest protiv glomerularne bazalne membrane (anti-GBM) je akutna i po zivot opasna sistemska autoimuna bolest. Pojava cirkulirajucih antitijela na citoplazmu granulocita (engl. anti-neutrophil cytoplasmic antibody, ANCA) u bolesnika sa anti-GBM glomerulonefritisom, tako zvana dvostruko pozitivna bolest (engl. double-positive disease, DPD), je vrlo rijetka. Prikazujemo 46 godisnju bolesnicu u koje je prvo klinicki i radioloski postavljena sumnja na upalu pluca, a koja se kasnije manifestirala sa pulmo-renalnim sindromom (PRS) odnosno DPD. Kompjutorskom tomografijom pluca dokazano je alveolarno krvarenje. Biopsijom bubrega dokazan je nekrotizirajuci glomerulonefritis (100 % glomerula). Imunoflorescencija je pokazala pozitivne linearne IgG depozite, sto odgovara anti-GBM glomerulonefritisu. U bolesnice su dokazana antitijela na mijeloperoksidazu p-ANCA i antitijela na glomerularnu bazalnu membranu. Lijecena je terapijskom izmjenom plazme (engl. therapeutic plasma exchange, TPE), hemodijalizom te kombinacijom parenteralne pulsne terapije kortikosteroidima, kasnije oralnom primjenom metilprednisolona i ciklofosfamida. Doslo je do regresije krvarenja u plucima ali se bubrezna funkcija nije oporavila, zbog cega smo nastavili s redovitim hemodijalizama. Ovaj prikaz bolesnice pokazuje kako u DPD, plucna simptomatologija moze biti vodeci simptom PRS sa urednom bubreznom funkcijom u pocetku. Rano prepoznavanja i dijagnoza su znacajni za pravovremeni pocetak lijecenja. Potrebno je naglasiti znacaj rane biopsije bubrega, ranog pocetka TPE te po potrebi i nadomjestanje bubrezne funkcije hemodijalizom. Kljucne rijeci: bolest protiv glomerularne bazalne membrane (anti-GBM), Goodpasturov sindrom, p-ANCA (anti-neutrofilna citoplazmatska protutijela), pulmo-renalni sindrom, brzoprogresivni glomerulonefritis s plucnom hemoragijom