Introduction Though cost-effectiveness analyses (CEAs) have evaluated continuous renal replacement therapy (RRTs) and intermittent RRTs in acute kidney injury (AKI) patients; it is yet to establish which RRT technique is most cost-effective. We systematically reviewed the current evidence from CEAs of CRRT versus IRRT in patients with AKI. Areas covered PubMed, EMBASE, and Cochrane databases searched for CEAs comparing two RRTs. Overall, seven CEAs, two from Brazil and one from US, Canada, Colombia, Belgium, and Argentina were included. Five CEAs used Markov model, three reported following CHEERS, none accounted indirect costs. Time horizon varied from 1-year-lifetime. Marginal QALY gain with CRRT compared to IRRT was reported across CEAs. Older CEAs found CRRT to be costlier and not cost-effective than IRRT (ICER 2019 US$: 152,671$/QALY); latest CEAs (industry-sponsored) reported CRRT to be cost-saving versus IRRT (-117,614$/QALY). Risk of mortality, dialysis dependence, and incidence of renal recovery were the key drivers of cost-effectiveness. Expert opinion CEAs of RRTs for AKI show conflicting findings with secular trends. Latest CEAs suggested CRRT to be cost-effective versus IRRT with dialysis dependence rate as major driver of cost-effectiveness. Future CEAs, preferably non-industry sponsored, may account for indirect costs to improve the generalizability of CEAs.