Phlegmasia caerulea dolens and venous gangrene are rare conditions that tend to occur in association with malignancy. They are characterized by total or near-total occlusion of the venous drainage of the limb, including the microvascular collaterals. Associated mortality and morbidity rates are high, especially when progression to venous gangrene has occurred. Treatment options are limited; elevation and anticoagulation are recommended as first-line management. Experience with thrombolysis has been disappointing although intra-arterial administration of thrombolytic agents may improve results. Thrombectomy cannot be advocated routinely. Little advance in management, or in life and limb salvage, has been made in the past 30 years.