Our purpose was to determine the incidence of deep-vein thrombosis (DVT) in patients who have had early operative fixation of fractures of the lower extremity distal to the hip. There is a high incidence of distal thrombosis in patients who have undergone early operative fixation of lower-extremity fractures. The incidence of DVT is higher with proximal extremity fractures than with distal extremity fractures. Most clots are occult and do not progress clinically. Given the high incidence of DVT with femoral and tibial plateau fractures, older age, and longer operating times, anticoagulation prophylaxis may be indicated. Ours was a prospective incidence study. All patients who had had early operative fixation of lower-extremity fractures were eligible (n = 176). Seventy-four were excluded based on specific criteria. The remaining 102 patients underwent lower-extremity venography an average of 9 days after operative fixation of their fractures (range 3-22 days). Eight patients had bilateral lower-extremity fractures. The patients were followed clinically for 6 weeks to identify complications related to venous disease. The overall incidence of clinically occult DVT was 28%. Of the represented fractures, 40% were of the femoral shaft (eight of 20), 43% of the tibial plateau (12 of 28), 22% of the tibial shaft (12 of 54), and 12.5% of the tibial plafond (one of eight). Four of the thrombi were proximal to the popliteal fossa. Four of the patients had clinical evidence of pulmonary embolism while in the hospital. One of them had objective confirmation on further testing. No patient had clinical evidence of pulmonary emboli as an outpatient by follow-up criteria. The incidence of DVT has not been determined for patients with early stabilization of lower-extremity fractures. This study suggests a higher DVT incidence in more proximal fractures, but little risk of embolization. Thrombus formation proximal to the popliteal fossa is rare. Older age, longer operating times, and longer times before fracture fixation all correlate with an increased incidence of DVT.