We present the case of a 74-year-old man with a past history of infrarenal abdominal aortic aneurysm. He consulted for abdominal pain. Cavitating pulmonary nodules and retroperitoneal fibrosis with periaortic alterations were detected on computed tomography. Laboratory investigations revealed that the patient was positive for cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA) and necrotizing granulomas were observed on biopsies of the lung lesions and retroperitoneal tissue. The patient was diagnosed with GPA and treatment was started with glucocorticoids and immunosuppressive agents, which led to a significant clinical and radiological improvement over the following months.