The main complications deriving from the use of vascular prostheses in the surgical reconstruction of the arteries are thrombosis, infection and the appearance of pseudoaneurysms. Among 233 aorto-femoral b.p., prosthetic thrombosis occurred in 45 patients creating the need for 66 reoperations, 19 early and 47 tardive. In 387 aorto-iliac reconstructions, infection arose early in 11 cases, tardively in 6. Out of 1118 vascular reconstructions there were also 28 pseudoaneurysms (2.5%). After remarks on the aetiopathogenesis of such complications, methods that can be used to prevent them are discussed and personal results of treatment are presented.