A case of Churg-Strauss vasculitis was studied by high-resolution computed tomography (HRCT) scanning. HRCT scanning demonstrated enlarged, irregular and stellate-shaped arteries, and small patchy opacities were present in the pulmonary parenchyma. These findings correlated with the histologic appearance of the pulmonary parenchyma on open lung biopsy. The arteries were enlarged due to eosinophilic infiltration in the vessel walls, and the adjacent lymphatics were dilated. This observation suggests that HRCT scans may be of value in the evaluation of pulmonary vasculitis because these findings are distinct from those of other diffuse lung lesions.