Venous thromboembolism (VTE) is associated with substantial morbidity and mortality. The clinical signs and symptoms are unspecific, widely varying from asymptomatic to sudden death. The diagnostic algorithm of VTE is an evolving field, in which D-dimers (DD) determination has been used as one of the preferred screening tests. Clinical management studies are clarifying the role of DD in the diagnostic paradigm of VTE. Published reports support the use of plasma DD determination in patients with a low clinical probability of VTE. Patients with moderate or high clinical probability of VTE show a higher probability of false negative plasma DD values. This fact forces the clinician to use more complex diagnostic test in order to either confirm or exclude VTE. A variety of different qualitative and semi-quantifiable assays are available for plasma DD determination. There is a wide variation in performance and there are discrepancies in the comparability of the different assays. Therefore, in order to both appropriately incorporate plasma DD determination in the diagnostic strategies of VTE and to reduce unnecessary investigations, clinicians should ensure that they are familiar with the diagnostic performance of the assay used in their own institution allowing a safer and cost-effective procedure.