Venous thromboembolism (VTE) has been on the rise in Japan in recent years, together with the Westernization of Japanese eating habits. According to the investigation by Editorial Committee on Guideline for Prevention of Venous Thromboembolism by Japanese Society of Anesthesiologists in 2002, 369 cases of pulmonary thromboembolism (PTE) were registered among 467 General Hospitals and University Hospitals. The rate of perioperative PTE is estimated to be 0.044% (369/837540), and the fatal rate among clinical PTE was 17.9%. 36% of the cases occurred in Orthopedics, 22% in general surgery and 10% in Obstetrics and Gynecology. 59% of the cases did not received prophylaxis, and 52% of the cases were restricted mobility. The incidence of clinical PTE after general surgery was 0.16% from 1994 to 2000 in Japan. Fatal rate among clinical PTE was 21.3%, and fatal rate among all patients was 0.04%. The incidence of clinical PTE after total hip joint replacement surgery among 46 papers between 1990 and 2001 in Japan was 1.1%, and that of fatal PTE was 0.15% among all patients. Patients of PTE were investigated between 1991 and 2000 among 68 University Hospitals and 34 General Hospitals in Japan. 76 cases of PTE occurred in Obstetrics, and 13.2% of them were fatal. The incidence of PTE was 0.003% in vaginal deliveries and 0.06% in cesarean sections. 178 cases of PTE occurred in Gynecology, and 13.5% of them were fatal. The incidence of PTE was 0.03% in benign diseases and 0.42% in malignant diseases. However, the incidence of PTE in Japan is considered to be at least one level lower compared with Western populations according to ACCP guidelines. Furthermore, low molecular weight heparin (LMWH) is not covered by health insurance and is contraindicated for pregnant women still now in Japan. Then, we established Japanese guidelines for VTE prophylaxis according to Japanese clinical evidences of PTE in 2004. We classified four risk groups according to ACCP guidelines. Recommended prophylaxis is early ambulation for low risk group, graduated compression stocking (GCS) or intermittent pneumatic compression (IPC) for moderate risk group, IPC or low dose unfractionated heparin (LDUH) for high risk group, and LDUH + IPC or LDUH + GCS for highest risk group. And, risk group should be raised one rank in cases with any additional risks, such as obesity, advanced age, pregnancy, operation time, and other complications. Recommended prophylaxis in this guideline may be minimum one, because the purpose of this guideline is to penetrate the awareness and education of VTE throughout Japan. Fortunately, the management fee for PTE prophylaxis was established and covered by health insurance in April 2004. However, after accumulation of further evidences and application of pharmacological agents, such as LMWH, we will establish the advanced guidelines in the future.