This study showed that the addition of a small dose of nalbuphine to bupivacaine in spinal anesthesia prolongs the time of postoperative analgesia. In addition the duration of intraoperative analgesia was prolonged, onset and level of sensory block were rapid and higher with the group of nalbuphine. All patients were assessed and monitored for : ECG for heart rate, and non-invasive arterial pressure, respiratory rate and arterial oxygen saturation, onset of sensory block, onset of motor block, duration of analgesia, duration of motor block, adverse effects as : hypotension, bradycardia, respiratory depression, urinary retention, pruritus, shivering, nausea and vomiting were recorded.