Administration of morphine with intravenous patient-controlled analgesia (PCA) is a routine technique in postoperative pain relief on laminectomy. In this study, we aimed to evaulate the effect of preemptive paravertebral somatic block with levobupivacaine on postoperative morphine consumption. After approval of the Medical Faculty Ethics Commitee and patient consent, aged 20-70 years, American Society of Anesthesiologist physical status I-II, 100 patients who were undergoing laminectomy, were included. Patients were randomly divided into 2 groups: 0.1 mg/kg intravenous boluse mophine was given to patients in the first group 20 minutes before the end of operation and intravenous PCA morphine (40 mg morphine in 100 mL isotonic saline, PCA demand dose 0.02 mg kg(-1), 20 min lockout time) was given after the operation. The patients in the second group were placed prone position after intubation, bilateral paravertebral somatic block was performed with 5 mL levobupivacaine 0,5% for each nerve to tipper dermatome of laminectomy level. Intravenous PCA morphine was started after the end of operation. All patients were recieved 8 mg ondansetron for antiemesis. Postoperative systolic and diastolic blood pressures, heart rate, peripheral oxygen saturation values, pain [Visual Analog Scale (VAS)] scores, total morphine consumption and side effects were recorded. Demographic data, operation times and hemodynamic parameters of groups were similar. VAS scores were higher in group 1 than group 2 on postoperative 4, 6, and 12 hours (P < 0.05). Total morphine consumption was recorded as 29.46 +/- 9.34 mg in group 1 and 2 and 88 +/- 7.28 mg in group 2 for 24 hours. Total morphine consumption was significantly lower in group 2 than group 1 (P < 0.05). We conclude that the application of preemptive lumbar paravertebral somatic block with levobupivacaine reduce morphine requirement, provides more efficient analgesia, without change in hemodynamic parameters or side effects.