Background: Nowadays use of spinal anesthesia is the preferred anesthesia technique forrncesarean section because it avoids air way related complication. But sometimes failed spinalrnanesthesia occurred and expose patient for pain and discomfort. rnObjective: To assess magnitude and associated factors of failed spinal anesthesia in a motherrnunderwent cesarean section at Addis Ababa governmental hospitals, Ethiopia from Decemberrn2018- May 2019. rnMethods: An institutional based cross sectional study was conducted on 794 mothers whornfulfilled inclusion criteria for elective and emergency cesarean section under spinal anesthesia atrnselected Addis Ababa governmental hospitals, Ethiopia from December 2018 – May 2019. Datarncollection methods include patient interview, chart review and observation of spinal anesthesiarnprocedure were employed for data collection. Collected data were entered in Epi info version 7rnand analyzed using SPSS version 20. Independent variables with the dependent variable werernanalyzed using logistic regression. A p-value of