Twenty-three cases of arterial injury after 8,208 arterial catheterizations for diagnostic or therapeutic indications at Glasgow Royal Infirmary are reviewed. Clinical presentation included haematoma formation, development of an acutely ischaemic limb or a false aneurysm. Patients with valvular heart disease are identified as a high risk group. Nine cases were managed by simple suture of the puncture site whereas thrombectomy and vein patch closure was required in 12 patients. The incidence of late complications requiring vascular reconstruction was 9%. The early recognition of complications after arterial catheterization and prompt referral to a specialized vascular unit is essential if morbidity is to be avoided.