Although the radiographic manifestations and pathologic features of Wegener's granulomatosis have been well described, their relationship to two variants of anti-neutrophil cytoplasmic antibodies (c- and p-ANCA) remains unclear. The purposes of this study are to analyze the radiographic and pathologic findings in 30 patients with Wegener's granulomatosis and to correlate c- and p-ANCA with such findings. Major histologic findings included parenchymal necrosis, necrotizing vasculitis, and granulomatous inflammations. Nodular lesions were more often associated with arteritis whereas patchy fluffy lesions associated with hemorrhagic capillaritis. ANCAs, particularly c-ANCA, instead of p-ANCA, were present in a high percentage of patients tested. These findings suggest that c-ANCA could play an important pathogenetic role in Wegener's granulomatosis which showed dual pathologic processes: vasculitis and granulomatous inflammation manifested radiographically as either nodular or pneumonia-like lesions, whereas p-ANCA was more often associated with patchy fluffy lung lesions as the consequence of hemorrhagic capillaritis.