How much should be done for better managements of the perioperative thromboprophylaxis? In Japan, the guideline for prevention of venous thromboembolism (VTE) was established for the first time in February, 2004. Our academic medical center formed a committee for prevention of thrombosis for all departments using operating rooms in October, 2002 and began to make the database of symptomatic pulmonary thromboembolism (PTE). From the end of September, 2003, we asked the surgeons to indicate the PTE risk grades when ordering surgical operations. The prevention team of VTE prepared VTE risk tables and recommended prevention methods for perioperative period. If surgeons did not choose prevention methods, the team took the consultation. Also, we made a manual how to make emergency calls and a flow chart for the diagnosis and therapy cooperating with cardiologists and anesthesiologists. We founded another meeting of Kinki Clinical Thrombosis Research Association for the study and education. We assessed the incidence of symptomatic PTE every year. The incidences of symptomatic PTE were 14 of 4101 (0.34%) in the first year, 2 of 3796 (0.053%) in the second year; 2 of 4002 cases (0.049%) in the third year under general anesthesia, respectively. Cases of fatal PTE were 2 (0.34%), 1 (0.049%) and 0 (0%), respectively. The multidisciplinary thromboprophylaxis effort that we had adopted was very important to prevent aggravation of VTE.