We have studied the diagnostic value for deep venous thrombosis (DVT) of an enzyme immunoassay (EIA) for the detection of D-dimer in plasma of 239 consecutive outpatients suspected of having DVT by their general practitioner. DVT was confirmed by impedance plethysmography in 60 patients. Using the 95th percentile range of 42 healthy volunteers, the sensitivity for the detection of DVT was 92 %, with a specificity of 21 %. In our population with a prevalence of 25%, the D-dimer EIA showed a negative predictive value of 88 % and a positive predictive value of 28%. We conclude that this D-dimer ELISA has limited value, either to confirm or to exclude DVT in outpatients.