Background: Nausea and vomiting during regional anesthesia for cesarean section are veryrncommon and unpleasant events. Can cause significant distress to the patient and interfere withrnthe surgical procedure. Identifying the factors of nausea and or vomiting during cesarean sectionrnin specific context can help to reduce negative consequence of nausea and or vomiting duringrncesarean section delivery.rnObjective: The objective of this study was to assess Magnitude of nausea and or vomiting andrnits associated factors among mothers taking spinal anesthesia for cesarean section at Gandhirnmemorial hospital, Addis Ababa, EthiopiarnMethods: Institutional based cross sectional study was conducted on 140 obstetric mothers whorngave birth under cesarean section with spinal anesthesia at Gandhi memorial hospital fromrnMarch to May 2017. Systematic random sampling technique was used to select study participantsrnfrom operation order during arrival. Necessary information was obtained from each mother andrnmedications, producers and vital signs were recorded. Bivariate and multivariate regressionrnanalyses were used to identify risk factor for the development of nausea and or vomiting. P valuernblow 0.05 was considered statistically significantrnResult: The overall magnitude of nausea and or vomiting was 54.3 %, Factors associated withrnpostoperative nausea and or vomiting were mothers who did not took metoclopramidernprophylaxis (AOR=2.958, 95% CI: (1.084-8.072), long duration of uterus exteriorizationrn(AOR=1.387, CI=1.109-1.734) and intraoperative shivering (AOR=6.133, CI=2.17-17.332)rnshowed strong odds of develop nausea and or vomiting than their counterpart.rnConclusion and recommendation: Nausea and or vomiting among mothers gave birth underrncesarean section with spinal anesthesia is significantly high. This study found that mothers whorndid not took metoclopramide prophylaxis, long duration of uterus exteriorization andrnintraoperative shivering were factors associated with nausea and or vomiting.rnWe recommended that metoclopramide prophylaxis should be administered before surgery