Pulmonary arteriovenous malformations are scarce and hard to diagnose. We report a case of a very late discovery at an advanced age. Recent vascular imaging techniques (Three-dimensional Computed Tomographic Angiography) have largely contributed to their diagnosis. The patient is treated with arterial embolization which is effective and carries a low complication rate in skilled hands. This case illustrates the clinical circumstances of diagnosis, the diagnostic algorithm, and the differential diagnosis to be discussed in this radio-clinical presentation, as well as the peculiarity of thinking about this malformation despite the advanced age.