Long-term follow-up studies demonstrated that venous thromboembolism is a chronic disease, as the rate of recurrent deep vein thrombosis (DVT) continuously increases after the primitive thrombotic episode. Objective testing is mandatory to confirm or refute the presence of recurrent DVT, as only 30% of patients with suspected recurrence have a new documented thrombotic episode. There is no consensus on the preferred diagnostic procedure; furthermore, both invasive and noninvasive methods are limited in this context. Venography, the established gold standard, is invasive, costly, inconvenient and requires high technical skills. Among noninvasive techniques, serial impedance plethysmography, alone or in combination with leg scanning and venography, and serial compression ultrasound (CUS), were adequately investigated. At present, the recommended approach is represented by a quantitative CUS method that possesses an excellent reproducibility and accuracy. The safety of withholding anticoagulants from patients with a normal quantitative CUS work-up has been recently demonstrated in a prospective management study.