Deep-vein thrombosis (DVT) is a common condition that can lead to complications such as postphlebitic syndrome, pulmonary embolism and death. The approach to the diagnosis of DVT has evolved over the years. Currently an algorithm strategy combining pretest probability, D-dimer testing and compression ultrasound imaging allows for safe and convenient investigation of suspected lower-extremity thrombosis. Patients with low pretest probability and a negative D-dimer test result can have proximal DVT excluded without the need for diagnostic imaging. The mainstay of treatment of DVT is anticoagulation therapy, whereas interventions such as thrombolysis and placement of inferior vena cava filters are reserved for special situations. The use of low-molecular-weight heparin allows for outpatient management of most patients with DVT. The duration of anticoagulation therapy depends on whether the primary event was idiopathic or secondary to a transient risk factor. More research is required to optimally define the factors that predict an increased risk of recurrent DVT to determine which patients can benefit from extended anticoagulant therapy.