OBJECTIVE To investigate the morbidity, relevant factors and diagnostic methods of lower extremity deep venous thrombosis (LEDVT) after gynecological pelvic surgeries. METHODS A prospective study was carried out investigating the morbidity, characteristics, risk factors, the coagulation function changes and diagnostic methods of LEDVT post-gynecological pelvic operations in 141 cases. Platelet, prothrombin time, activated partial thromboplastin time, fibrinogen, thrombin time, D-dimer, antithrombin-III, tissue plasminogen activator, plasminogen activator inhibitor were measured within 1 week before surgeries, 48 hours and 5 - 7 days post-surgeries respectively. Color Doppler flow imaging was performed simultaneously. RESULTS (1) Twenty-two cases were found with LEDVT, the morbidity of LEDVT after gynecological procedures was 15.6%. It occurred 2 - 7 days post operation. (2) The risk factors were bedfasting, coagulant prescription post-operation, cardiovascular disease, ageing, pelvic lymphadenectomy, general anesthesia, and malignancy. Multivariate regression showed only age and coagulant prescription post-operation were independent factors. (3) The level of D-dimer was (0.9 +/- 0.6) mg/L in LEDVT group, significantly higher than that of non-LEDVT group [(0.5 +/- 0.4) mg/L, P < 0.01]. The positive predictive value and negative predictive value of D-dimer were 30.8% and 98.6% respectively. (4) Among 22 cases who were diagnosed with LEDVT by compression duplex ultrasound, only 4 cases performed lower extremity venography, and the diagnosis was confirmed. CONCLUSIONS The morbidity of postoperative lower extremity deep venous thrombosis in gynecological procedures was high. The combination of D-dimer and compression duplex ultrasound examination was applicable to the diagnosis of LEDVT. The optional duration of the examination was 2 - 7 days post operations.