Aim: To evaluate hemodynamic repercussion of a protocol of spinal anesthesia (SA) for cesarean and release the predictive factors of maternal arterial hypotension post spinal anesthesia., Methods: We included parturients proposed for Cesarean under SA. They were not included the women of statute ASA > II, preeclamptics, eclamptics and/or having counter-indications of SA. We excluded the cases where there were technical difficulties at the time of the realization of SA, a failure or a complication of this SA. We injected 10 Mg of bupivacaïne 0.5% isobar, 10 μg of fentanyl and 100 μg of morphine. The data were collected before the realization of SA (anthropometric parameters; antecedents; basic systolic and diastolic blood pressures (BSBP and DSBP) and basic heart rate (BHR)) and after SA (systolic and diastolic blood pressure (SBP and DBP), heart rate (HR); occurred or not of a sympathetic block (falls of the SBP of more than 20% of its basic value or a SBP<90 mm Hg); the time of installation of the sympathetic block and the duration of hypotension., Results: The full number of parturients included was 1016 among whom 16 were excluded. Only 1000 parturients finished the study and were divided into 2 groups (group 1: 500 emergency cesarean and group 2: 500 elective cesarean). The incidence of the sympathetic block was of 44.2% as a whole and this block was significantly more frequent in group 2 (p=0.0001). There was a significant relation between the incidence of a sympathetic block and the advanced age of the parturient (p=0.0001), the important weight (p=0.047), high ASA statute (p=0.0001), the presence of hypertension (p=0.0001), diabetes (p=0.001) or cesarean (p=0.00015) in the antecedents and the low BSBP (p=0.015)., Conclusion: In spite of the beneficial effect of the reduction in the amounts of local anesthetic in the SA, the sympathetic block remains frequent after SA for Cesarean. Thus, it is essential to detect the high risk women of occurred of sympathetic block after SA, and to propose strategies of prevention, monitoring and management for this population.