The efficacy of dexamethasone and ondansetron on intra and postoperative nausea and vomiting is confusing and still debatable. We conducted this systematic review and meta-analysis to synthesize evidence from published studies on the efficacy and the impact of dexamethasone and ondansetron for cutting the risk of nausea and vomiting in pregnant women. We followed the standard methods of the Cochrane Handbook of Systematic Reviews for interventions and the PRISMA statement guidelines 2020 when conducting and reporting this study. A computer literature search-of PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials-conducted from inception until January 2022. We selected randomized controlled trials (RCTs) assessing the efficacy of dexamethasone alone Vs combination of dexamethasone and ondansetron, on nausea and vomiting in pregnant women undergoing cesarean section. All relevant outcomes were pooled in the meta-analysis using Review Manager Software. Five RCTs were included in our study with only four RCTs included in the meta-analysis.The pooled risk ratio suggested that there is no significant difference between Ondansetron and combination or dexamethasone in reducing preoperative vomiting as following respectively: [RR=1.9,95%CI (0.164,22.2), P= 0.605], and [RR=0.549, 95%CI (0.160,1.882), P=0.17]. Also, regarding pre-operative nausea there is no significant difference between ondansetron and combination or between dexamethasone and combination as following: [RR =0.7,95%CI (0.3,1.64), P=0.41], and [RR =1.91,95%CI(0.98,3.71),P=0.06]. while combination intervention reduces the incidence of post-operative nausea and vomiting compared to both ondansetron and dexamethasone as following respectively:[ RR Print