Abstract: Objective To compare the block characteristics of levobupivacaine and bupivacaine for hypobaric unilateral spinal block. Methods Sixty patients undergoing hypobaric unilateral spinal block for lower extremity operations were randomized into 2 equal groups. In one group the patients were asked to lie on the uncompromised side for slow injection of hypobaric bupivacaine solution (0.75% 6 mg, diluted to 2 ml with distilled water) at the rate of 1 ml/15 s through a 27-gauge needle. The patients maintained their position for 15 min before shifting to a supine position. In the other group levobupivacaine was used instead. Results Statistical study showed that the block characteristics were of no significant difference between the 2 groups (P>0.05) except that the duration of motor block was shorter in levobupivacaine group than in bupivacaine group (P<0.05). Blood pressure or heart rate showed no significant difference between the two groups during operation. Conclusion The block characteristics of hypobaric unilateral spinal block with levobupivacaine or bupivacaine are similar and their effect on circulatory function is slight. Levobupivacaine provides an option in case bupivacaine is not available.