Continuing our characterization of the immunopathological events occurring during experimental murine Chagas' disease, an immunohistological examination was conducted of the aortas of chronically infected CBA/J mice. Compared with non‐infected mice of identical age, Trypanosoma cruzi‐infected mice exhibited a marked vasculitis, with significant infiltration of inflammatory cells into the adventitial layer, including CD4+, CD8+ T cells and macrophages. Production of interleukin‐6 (IL‐6) and tumour necrosis factor‐α (TNF‐α) was evident in the inflammatory infiltrate in the endothelial and smooth muscle layers. Vasculitis was most apparent in proximity to the heart, but extended along the aorta. Such an inflammation could lead to an alteration of the endothelium, altering the protective properties of this layer and further contributing to the focal pathology characteristic of this stage of infection.