A case of pulmonar parasitosis caused by Aelurostrongylus abstrusus in (Railliet, 1898) a adult cat is described, with clinical monitoring, laboratory and imaging test, and treatment for 14 months. During follow-up, the cat presented larvae of A. abstrusus in the Baermann parasitological methods and in the fecal smear with treatments and relapses of the parasite in the exams. Radiographic images showed diffuse opacification of the lung fields with an interstitial pattern, tending to alveolar, with visualization of thickened bronchial walls, related to an inflammatory/infectious process. The persistence of lungworm disease is discussed and the treatment.