BACKGROUND: The present study was aimed to determine the alterations of hemodynamics and embolic composition during the course of total knee replacement. METHODS: A retrospective analysis was performed using data acquired from 20 patients who underwent 10 unilateral and 10 bilateral total knee replacement under general anesthesia. Transesophageal echocardiography and Swan-Ganze catheterization were placed following induction of anesthesia, then images and changes were recorded throughout the procedure. All patients were performed using fluted intramedullary rods inserted into an overdrilled femoral entrance hole in conjunction with the application of a tourniquet. RESULTS: We found echogenic emboli in 8 out of 20 patients during cannulation of the femoral canal and performing femoral and tibial saw cuts, then we detected echogenic emboli in all 20 patients during tourniquet deflation. Echogenic emboli consistently filled the right atrium and ventricle with very small size embolic materials for 19 7 minutes during total knee replacement. Heart rate exhibited no change, Mean arterial pressure decreased and mean pulmonary artery pressure increased after tourniquet deflation. After tourniquet deflation, free fatty acid increased in lipid profile. No patient had postoperative complications related echogenic emboli. CONCLUSION: All patients exhibited echogenic emboli during certain stages of total knee replacement. Although all patients were asymtomatic in our study, one should be cautioned when performing total knee replacement in patients with little physiologic reserve and large embolic events.