Aim of the study: To compare unilateral spinal anesthesia (USA) and conventional spinal anesthesia (SA) in elderly patient undergoing surgery for upper extremity of the femur fracture. Methodology: It was a prospective descriptive analytical randomized study of 16 months including 42 patients carried out in the departments of anestesiology and orthopedics-traumatology of the National Hospital of Niamey. The patients were randomized in two groups: the first group unilateral spinal anesthesia (USA) received a dose of 7.5mg of Bupivacain with 25ɤ of Fentanyl; the second group conventional spinal anesthesia (SA) received 12.5mg of Bupivacain with 25ɤ of Fentanyl. The choice of the administrated dose of Bupivacain were random and alternated half the time. Results: During the time of our study, we registred 42 patients we divided in two groups of 21. In the intraoperative period, the mean arterial pressure (MAP) and the mean heart rate (HR) were comparative in the two groups of patients. There was no difference in the time to installation of the sensory and motor block (7mn and 9mn in USA group vs 7mn and 8mn in conventional SA, P-value=0.79) and neither in it’s duration (153.1mn and 162.8mn in USA group vs 176.5min and 182.81mn in conventional SA group, P-value=0.1 and 0.14). The dose of ephedrine used intraoperative was 14.40mg in conventional SA group and 19.20mg in USA group, the difference were not statistically significant (P-value=0.36). Fluid replacement was done in the two groups with an average of 1.74L in USA group and 1.62L in conventional SA group, with no statistically significant difference (P-value=0.87). The pain was also comparative in the two groups up to 18hours postoperative. The difference in the intensity of this pain was statistically significant between 18hours and 24hours, it was more important in USA group however releived by analgesics of level 1 (P-value=0.002). Intra and postoperative complications were comparative in the two groups ...