Long-term anticoagulant treatment is highly effective in preventing recurrent Venous Thrombo-Embolism (VTE) in patients with idiopathic Deep Vein Thrombosis (DVT) of the lower limbs, though associated with an increased risk for major bleeding that may offset the benefits of anticoagulation. Accordingly to recent guidelines, patients with idiopathic DVT should be treated for at least 3 months and then should be evaluated for the risk-benefit ratio of long-term therapy. However, such 'time for decision' is often unclear and the optimal duration of VKA remains debatable. In recent studies, markers for the assessment of the individual risk for recurrent thrombosis have been proposed, which can be of help to establish the optimal duration of VKA treatment; among them, the D-dimer (D-d) assay and the Residual Vein Thrombosis (RVT) assessment by Compression Ultra-Sonography (CUS) were shown to be the most suitable. Studies' results showed that negative results of these parameters after 3 to 6 months of therapy, identify a group of patients at low-risk for recurrent thrombosis in whom VKA treatment can be withheld. In the present review we will discuss advantages and potential limits of using these individual markers for the management of patients with a first episode of DVT of the lower limbs.