Calf vein thrombosis is a much-debated entity. The literature shows that progression to deep venous thrombosis or pulmonary embolism occurs infrequently and is usually detected using serial two-point ultrasonography. Additionally, undetected and untreated calf vein thrombosis is not associated with serious adverse events in large management trials studying diagnostic strategies for suspected deep venous thrombosis. Recurrent venous thromboembolism can occur after calf vein thrombosis, but anticoagulant treatment does not reduce the incidence. In this article, three case histories describe the anatomical considerations for proper diagnosis of calf vein thrombosis, some aspects of the natural course, and the treatment that these patients received. A case is made for restrictive use of prolonged anticoagulation therapy as a means to reduce thromboembolic complications. Because symptomatic treatment has not been studied, expert opinion suggests a short (3-week) course of therapeutically-dosed low-molecular-weight heparin.