Background: Bupivacaine was introduced to be a long-acting spinal anesthetic agent. It has been argued about whether the addition of epinephrine prolongs the bupivacaine action or not. The aim of this present investigation was to find out the effect of additional epinephrine on spinal anesthesia with bupivacaine. Methods: 47 patients undergoing an operation on lower extremity were randomly allocated to 2 groups. All patients were anesthetized by subarachnoid block with 0.5% bupivacaine in 8% glucose, which was mixed with 0.2 ml of normal saline in group non-E (n=24) and 0.2 ml of 1:1,000 epinephrine in group E (n=23). We evaluated blood pressure and heart rate, the sensory and motor blockade and voiding time after spinal anesthesia. Results: The systolic blood pressure (SBP) at 8 and 10 min after anesthesia were lower in group non-E than in group E (p<0.05). The trend of decreasing diastolic blood pressure was similar in both groups. The heart rate(HR) at 2 min after anesthesia was lower in group non-E than in group E (p<0.05). The sensory block in T10 was produced faster in group non-E (7 min) than in group E (11 min)(p<0.05). And the maximal sensory block level and its reaching time was T7 and 14 min in group non-E, and T8 and 17 min in group E (p=0.12, p=0.11). Two segment regression time was 124 min in group non-E, and 184 min in group E (p=011). The onset time of motor block to Bromage scale 3 was 12 min in group non-E and 16 min in group E (p=0.06). The recovery time from complete motor block to Bromage scale 1 after maximal motor block was 263 min in group non-E, and 278 min in group E. The time at which patients voided after anesthesia was 469 min in group non-E, and 466 min in group E. Three patients urinated by using a urinary catheter in each group. Conclusions: The addition of epinephrine to bupivacaine for spinal anesthesia can slow the decrease in SBP and increase the HR at early stage of anesthesia, and slow the sensory block.