In this report, we investigated that what kind of prophylaxis method for VTE after operation were used in our hospital, how was the frequency of VTE after operation and which factors related to VTE. From August first to December 28th 2009, we had 266 patients who underwent many kind of elective operations at three department of Miyazaki University Hospital. The departments consisted of the thoracic, abdominal, cardiovascular surgery, orthopedic surgery and obstetrics/gynecology. D-dimer level in the blood was examined at three points, pre- and the third and seventh post-operative day. Patients with high D-dimer level over 1.00μg/ml on pre- and over 10.00μg/ml on the seventh post-operative day were examined the lower extremities by ultrasonography. We found 7 patients with DVT before operation and 9 patients after operation. There were no patients presented PTE. Orthopedic surgery, malignant disease, postoperative IPC, period of bed rest, D-dimer level on the third post operative day were proved as independent predictive factors by univariate analysis. D-dimer level on the third post operative day and orthopedic surgery were proved as predictive factors for DVT by multivariate analysis. In conclusion, postoperative VTE prophylaxis in our hospital was thought to be appropriate in some degree. However, more sophisticated screening measure for DVT detection is strongly desired.