OBJECTIVE: To study the effects of a passive exercise in hemiplegic lower limb on the blood flow velocity in the femoral vein compared with functional electrical stimulation. METHOD: Twenty stroke patients (men 11, women 9) were enrolled. The patients lied down on a table for 15 minutes. Then the investigator performed passive exercise, flexion and extension of the hip, knee and ankle joint of the hemiplegic limb, for 5 minutes with frequency of 1 Hz. At least 24 hours later, functional electrical stimulation was performed to tibialis anterior and gastrocnemius muscles for 20 minutes. We collected the peak blood velocities of the femoral vein before and 0, 15, 30, 45, and 60 minutes after each procedure. RESULTS: The peak blood flow velocities of the femoral vein before passive exercise were 10.3+/-1.34 cm/sec and 15.4+/-2.22, 14.5+/-1.86, 13.0+/-1.58, 11.4+/-1.23, 10.4+/-1.17 cm/sec at 0, 15, 30, 45, 60 minutes after exercise. There were significant differences until 30 minutes after exercise (p<0.01). The velocities of the femoral vein were 10.6+/-1.36, 18.2+/-2.34, 16.6+/-2.1, 14.6+/-1.7, 12.6+/-1.7, 11.5+/-1.5 cm/sec for before and 0, 15, 30, 45, 60 minutes after functional electrical stimulation. There were significant differences until 45 minutes after FES (p<0.01). CONCLUSION: The passive exercise of hemiplegic lower limb for 5 minutes was effective for increase of femoral blood flow. It may be a good method for preventing a DVT after stroke.