Abstract: To study the prevalence of DVT in patients with pulmonary embolism(PE),~(99)Tc~m-MAA lower extremity vein scan is performed in 71 PE patients.The results show that 55 of 71 PE patients are found with DVT,and 32 cases are found with DVT in 36 PE patients with symptoms of DVT,while in 35 PE patients without symptoms of DVT,23 cases are found with DVT.Asymptomatic DVT is often found in distal veins,while symptomatic DVT in proximal veins.~(99)Tc~m-MAA lower extremity vein scan could detect both asymptomatic DVT and symptomatic DVT,so it should be used as a routine examination in PE patients before lung perfusion scan is done.