The authors report the case of a 30-year-old woman with Takayasu's disease revealed by acute leg ischemia and complicated by abortion during the fourth month of pregnancy. Clinically suspect lesions were confirmed by angiography showing a severe stenosis at the aorto-iliac bifurcation complicated by overlying mild ectasic lesions and a large thrombus. A total occlusion of embolic origin was noted in the right popliteal artery. An attempt to open up the thrombosis at the bifurcation led unfortunately to massive rethrombosis requiring implantation of an aorto-iliac prosthesis. Histopathological examination of the aortic surgical specimen indicated Takayasu's disease; the placenta showed multiple infarcts. The complete angiographic study revealed no arterial involvement in any other region. Five months after the initial operation, rapid development of claudication in both lower limbs suggested stenosis at the prosthesis implantation sites which was confirmed by angiography. Initiation of general corticosteroid therapy led to partial remission in less than two weeks. The unusual feature in this case was the revelation of the affection by distal arterial embolic manifestations, which have been reported only exceptionally in the literature. Moreover, isolated involvement of the aorto-iliac bifurcation constitutes a rare form of Takayasu's disease. With respect to therapy, the implantation of a prosthesis was complicated by severe stenoses of the junction zones, which is unfortunately an event in the course of this affection. The normality of biologic inflammation studies did not suggest an initial need for corticosteroid therapy, especially in the case of an isolated arterial manifestation.(ABSTRACT TRUNCATED AT 250 WORDS)