For the estimation of fibrinolytic activity in euglobulin precipitates after venous stasis, the euglobulin clot lysis time (ECLT) proved to be as reproducible and probably even more sensitive than the fibrin plate method (FP). Furthermore, when euglobulin precipitates from 55 healthy individuals and 36 patients with thromboembolic disease were examined, a good correlation between the two methods was observed. The present observations indicate that the ECLT is suitable for routine screening of fibrinolytic activity after venous stasis.