The pattern of arterial occlusion in Buerger's disease was analyzed by simultaneous bilateral femoral arteriography in 210 limbs of 105 patients with Buerger's disease. In 55 limbs of 42 patients, the femoropopliteal segment was affected in addition to the infrapopliteal arterial obstructive lesion. The pattern of crural arterial occlusion was similar in about 40% of both the patients with femoropopliteal occlusion and the patients with crural occlusion. Toes were ulcerated in 4 of 58 limbs with continuous arterial flow, and ulceration occurred in 86 of 152 limbs with a discontinuous flow. The rate of occurrence of bilateral trophic lesion in the group with an arterio graphically similar occlusion pattern was not significantly higher than that in the group with a different pattern. The pattern of arterial occlusion in Buerger's disease seemed to be fixed mainly within 1 year after the onset of symptoms, and the skip-lesion in the main artery was favorable to proximal progression of the disease.