Eighty-seven popliteal aneurysms in 62 patients, of which 50 were treated surgically, were reviewed and their clinical characteristics summarized. The need for alertness in the clinical detection of these lesions was stressed. Because complications, namely thrombosis and embolization, were frequent (23% in the total group, 36% in the surgical group), we recommend surgical treatment not only in all symptomatic but also in asymptomatic aneurysms larger than 2 cm in diameter; nonsurgically treated cases must be followed up carefully. With this aggressive approach, no lives and only two limbs were lost (one in a case of irreversible gangrene of the foot). Of the two surgical techniques described, the bypass procedure with autogenous vein graft is, because of its simplicity, given preference over resection with graft.