Aim: To estimate the incidence of VTE in Indonesian patients undergoing major orthopedic surgery and not receiving thromboprophylaxis.Methods: This was an open clinical study of consecutive Indonesian patients undergoing major orthopedic surgery, conducted in 3 centers in Jakarta. Bilateral venography was performed between days 5 and 8 after surgery to detect the asymptomatic and to confi rm the symptomatic VTE. These patients were followed up to one month after surgery.Results: A total of 17 eligible patients were studied, which a median age of 69 years and 76.5% were females. Sixteen out of the 17 patients (94.1%) underwent hip fracture surgery (HFS). The median time from injury to surgery was 23 days (range 2 to 197 days), the median duration of surgery was 90 minutes (range 60 to 255 minutes), and the median duration of immobilization was 3 days (range 1 to 44 days). Thirteen out of the 17 patients were willing to undergo contrast venography. A symptomatic VTE was found in 9 patients (69.2%) at hospital discharge. Symptomatic VTE was found in 3 patients (23.1%), all corresponding to clinical signs of DVT and none with clinical sign of PE. These patients were treated initially with a low molecular weight heparin, followed by warfarin. Sudden death did not occur up to hospital discharge. From hospital discharge until 1-month follow-up, there were no additional cases of symptomatic VTE. No sudden death, bleeding complication, nor re-hospitalization was found in the present study.Conclusion: The incidence of asymptomatic (69.2%) and symptomatic (23.1%) VTE after major orthopedic surgery without thromboprophylaxis in Indonesian patients (SMART and AIDA), and still higher than the results of the Western studies. A larger study is required to establish the true incidence, and more importantly, that the use of thromboprophylaxis in these patients is warranted. (Med J Indones 2009; 18: 249-56)Keywords: venous thromboembolism (VTE), orthopedic surgery, Indonesia