OBJECTIVE With the objective of finding a safer drug than racemic bupivacaine, several animal studies were performed with its enantiomers. This study aimed at evaluating the efficacy of 0.5% bupivacaine enantiomeric mixture (S75-R25) as compared to 0.5% bupivacaine in lumbar epidural anesthesia for lower limb orthopedic surgery. METHODS Participated in this randomized double-blind study 38 adult patients, aged 17 to 69 years, physical status ASA I and II submitted to lower limb orthopedic surgery, who were distributed in two groups: Group B - 30 ml of 0.5% bupivacaine and Group BEM - 30 ml of 0.5% bupivacaine enantiomeric mixture (S75-R25). Sensory and motor block characteristics were investigated, in addition to the incidence of side effects. RESULTS There have been significant weight differences in group BEM. Hemodynamic parameters were similar in both groups. There were no differences in time to reach Bromage score and peak block height. Also time to total motor block regression was similar between groups. There has been a significant difference in Bromage 2 score between groups, which was higher in group BEM. CONCLUSIONS Adequate sensory and motor block for surgery was achieved in both groups with few side effects, suggesting that both solutions are safe in lumbar epidural anesthesia for orthopedic surgery.