A histological investigation of the vascular changes of three major and lingual minor salivary glands in primary Sjögren's syndrome was carried out on eight autopsied Japanese patients. This study compares vascular lesions in salivary glands between one group of four short-term corticosteroid-treated patients (Cases 1, 3, 4 and 7) and the other group of four long-term corticosteroid-treated patients (Cases 2, 5, 6 and 8). We proposed the following five stages for morphogenesis of arteritis; (1) endothelial swelling, (2) thrombosis, (3) fibrinoid degeneration, (4) necrotizing panarteritis and (5) endarteritis obliterans. Endothelial swelling was seen in small-to-large arteries of major salivary glands and the tongue, and this finding was considered as the initial change of vascular lesion. Thrombosis was observed in the small arteries of both organs. Fibrinoid degeneration and necrotizing panarteritis were predominantly localized in small and middle-sized arteries. Endarteritis obliterans was observed in small and large arteries of major and lingual minor salivary glands in primary Sjögren's syndrome. Vascular lesion of this type was common in the four patients who received corticosteroid for more than 12 months. Corticosteroid therapy appears to accelerate the fibrotic change of the vascular wall. Therefore, we suggest that essential vascular lesions of major and lingual minor salivary glands in primary Sjögren's syndrome may include four types (endothelial swelling, thrombosis, fibrinoid degeneration and necrotizing panarteritis), excluding endarteritis obliterans.