Since in stage II of peripheral arterial disease (PAD), according to the definition, there is no objective evidence of danger for the involved extremity, management is dependent on the extent to which the claudication complaints are tolerated (Figure 1). If well tolerated, observation and treatment of risk factors, possibly enrollment in an out-patient training group, are sufficient. Exceptions are the cases of pending danger to viability as well as isolated stenoses in the pelvic region or larger leg arteries easily amendable to percutaneous dilatation. If the patient does not tolerate the complaints, for aortic and pelvic artery occlusions, training of the muscles of the upper thigh is indicated, for occlusions in the thigh training of the calf musculature is warranted. The pathophysiologic basis of training lies in an increase in perfusion via collaterals due to dilatation of the muscular arterioles distal to the stenosis incurred by virtue of work and ischemia. This mechanism may also involve a sheer-induced release of endothelium-derived relaxing factor. Over a moderate period of time, there is an organic increase in collateral caliber due to the perfusion-dependent growth stimulus. A further effect of training is an increase in metabolic activity. If training is unsuccessful, lumen enlarging measures ("LEM" in Figure 1) should be considered. Indications for percutaneous transluminal angioplasty (PTA) are stenoses in the pelvic region or large leg arteries as well as short occlusions of the femoropopliteal vessels (less than 10 cm). With the help of special techniques like rotational angioplasty even occlusions of the pelvic arteries are treatable in selected cases. The five-year patency rate of dilated pelvic artery stenoses is 82%, three-year patency rate for femoral artery stenoses 81% and femoral artery occlusions 78%. Among newer procedures are laser and auger angioplasty, catheter atherectomy and stents. The question of efficacy of platelet inhibiting drugs of the aspirin type, with regard to prophylaxis of early and late re-stenosis remains unsettled. In principle new medical approaches are selective inhibition of thromboxane as well as inhibition of arteriosclerosis-induced proliferation and migration of active mediamyocytes, for example, with highly negative-charged polyanions. For the prophylaxis of peripheral arterial occlusion with aspirin, a dosage of one to 1.5 gram daily would seem appropriate until studies are available to document the effects of lower dosages.(ABSTRACT TRUNCATED AT 400 WORDS)