Colour coded Duplex sonography has definite advantages over duplex sonography for the investigation of neck and limb vessels. Diagnosis of arterial stenoses, occlusions and aneurysms can be readily made. The method also allows to follow the evolution after vascular surgery and percutaneous transluminal angioplasty. Deep venous thromboses can be reliably detected without the use of contrast media. Application for abdominal vascular diagnosis is still limited.