Introduction: Spinal anesthesia is a type of regional anesthesia, has been practiced for rnobstetric anaesthesia since the beginning of the 20rnthrn century.so it is easy to perform andrnreliable as well avoids the depressant effects of anesthetic drugs and has a potential tornprovide excellent operating conditions for caesarean section. Hypotension is a usualrnconsequence of sympathetic motor and sensory block caused by spinal anesthesia forrncesarean section. rnObjectives: The objective of the study is to determine the incidence and associated factorsrnfor hypotension after spinal anesthesia during cesarean section at Gandhi memorial hospital,rnAddis Ababa, Ethiopia. rnMethod: Institutional based cross sectional study was conducted on 422 clients usingrnstructured questionnaire until the end of the operation. The study was conducted on cesareanrnsection under spinal anesthesia from January, to April 30, 2019 at Gandhi memorial Hospital,rnAddis Ababa, Ethiopia. Systematic random sampling technique was used for selecting thernsample. Both bivariate and multivariate logistic regression analysis were done for associatedrnfactors. Level of statistical significance was declared at p-value less than 0.05. rnResults: The incidence of hypotension among mothers who undergone cesarean section afterrnspinal anesthesia was 64%. Neonate weight of 2.5-3.9kg AOR=3.440; 95% CI:( 1.441-8.211)rnand greater than 4kg AOR=4.957; 95%CI: (1.563-15.722) showed increased association withrnhypotension. A baseline systolic blood pressure less than 120mmHg AOR= 5.527; 95%CI:rn(2.695-11.336), and in the range of 120-130mmHg AOR=3.583; 95%CI: (1.980-6.485) wasrnassociated with hypotension. Sensory block height >T6 AOR= 2.272; 95%CI: (1.362-3.788)rnand the time interval between spinal induction and skin incision > 6minutesrnAOR=1.758;95%CI: (1.022-3.024) are also associated with hypotension after spinalrnanesthesia. rnConclusion: The risk of hypotension is high in cesarean section after spinal anesthesia. Thernidentified risk factors for spinal anesthesia induced hypotension are sensory height block,rnweight of the baby, time interval between spinal induction and skin incision, the baselinernsystolic blood pressure and experience of anesthetist.