Chronic venous insufficiency is a debilitating condition. It affects about 0.2% of the population and is very demanding on health resources. In the UK, there are about 100,000 patients with active leg ulcers and treating these patients costs the national health service between £100 and £400,000,000 per anum. This paper reviews the classification, epidemiology, pathophysiology, investigations and treatment of this condition. The etiology of venous ulceration is discussed and the various theories explaining the cause of ulceration examined. The latest research into the condition is reviewed and the relative roles of superficial venous incompetence and deep venous incompetence in the pathophysiology of ulceration is presented. Surgical and non-surgical treatment of the condition including surgical treatment of superficial and deep venous incompetence, compression therapy, and drug therapy is explored.