Noninvasive investigative methods are valuable for the practical diagnosis of several peripheral vascular disorders. Doppler ultrasound is very useful for the detection of incompetent saphenous and perforating veins and for the measurement of systolic ankle pressure, which today is the best screening method for arterial stenoses or occlusions. Acral oscillography, photoplethysmography and thermography, combined with vasodilator (nitroglycerin) or vasoconstrictor (cold) stress tests, may disclose small vessel disease and vasospastic disorders (Raynaud phenomenon). To answer the question of whether varicosities should be eliminated by surgery or sclerotherapy in patients with severe stages of chronic venous insufficiency (e.g. crural ulcers), investigations of the venous pump by venous pressure measurement or (photo-)plethysmography with and without digital occlusion of the suspected leakage points are recommended. Doppler probe, plethysmography and thermography are valuable screening methods for deep vein thrombosis and help to restrict phlebography to patients on whom fibrinolysis or thrombectomy is carried out. For the majority of patients undergoing conservative treatment, these noninvasive diagnostic procedures are usually sufficient.