Eosinophilic angiocentric fibrosis (EAF) is a rare condition of unknown etiology that causes stenosis of the upper respiratory tract. We report one case in which immunohistochemical studies were performed that involved the mucosa of the lateral nasal wall and septum of a 54-year-old woman. The lesion showed areas with vascular proliferation, small-vessel vasculitis, and dense inflammatory infiltrate consisting of T lymphocytes, macrophages, polyclonal plasma cells, and numerous eosinophils and neutrophils. Other areas were hypocellular and fibrotic, and in those, the collagen bundles showed perivascular onion-skin whorling. The clinical and histologic similarities between our case and those previously described, in addition to the immunohistochemical findings, support the hypothesis that eosinophilic angiocentric fibrosis is a chronic inflammatory condition with a peculiar and striking stromal response.