Background: Acute kidney injury (AKI) is a public health problem that affects millions of hospitalized patients worldwide. In Argentina, evidence suggests that its incidence has risen in recent years. When severe, AKI may require a renal replacement therapy (RRT) where continuous RRT (CRRT) and intermittent RRT (IRRT) are plausible options for patients in the intensive care unit. Objective: To evaluate the cost utility of CRRT versus IRRT for the National Institute of Social Services for Retirees and Pensioners, the largest social security health insurance for elders in Argentina. Methods: This was a model-based cost-utility analysis. Long-term costs and health outcomes were estimated for a hypothetical cohort with a Markov model. Parameters used were obtained from published literature and validated with local experts. Local costs were estimated and expressed in $AR of 2016. Several sensitivity analyses were run to analyze the impact of uncertainty on results. Results: Continuous RRT dominated IRRT by cumulating over the model more quality-adjusted life years and less costs. Total discounted quality-adjusted life years for both cohorts were 1049 and 1034, respectively, and total costs were $95 362 and $103 871. Cost-effectiveness (CE) results reflect these differences in favor of CRRT with a deterministic cost-saving incremental CE ratio and a probability of CRRT being CE of 65.4%, considering a CE threshold of 1 gross domestic product per capita. Conclusions: Continuous RRT for patients with AKI eligible for CRRT or IRRT would probably be a cost-effective intervention for the National Institute of Social Services for Retirees and Pensioners’ view. Nevertheless, there is considerable uncertainty around results, mainly due to the lack of adequate controlled studies and local data on the prognosis of these patients in Argentina.