False aneurysm is an infrequent but serious complication of endarterectomy of the carotid bifurcation. From 1958 to 1971, a total of 898 endarterectomies on the carotid bifurcation were performed at the University of California, San Francisco, for atherosclerotic occlusive disease. During this period three false aneurysms developed, and another false aneurysm was treated following a primary operation at another hospital. All four patients, in two of whom local Staphylococcus infection was documented, were successfully reoperated upon by application of autogenous techniques. Blood flow to the internal carotid artery was preserved in each instance, and no new neurologic deficits occurred. This experience plus review of previously reported cases of postoperative false aneurysm of the carotid artery point up the value of the use of autogenous tissue in their repair.