<p>Acute normovolemic hemodilution (ANH) is an intraoperative blood conservation technique that involves removing a portion of the patient’s blood after anesthesia induction and replacing it with fluids to maintain normovolemia. The purpose of this systematic review and meta-analysis was to assess the efficacy and safety of ANH in reducing transfusion requirements and improving hemorrhagic outcomes in adult cardiac surgery patients. Studies were identified through systematic searches of PubMed, Embase, and Cochrane Central databases. Effect estimates were calculated using random-effects models, with heterogeneity assessed using the I² statistic. Trial sequential analysis (TSA) was employed to evaluate the robustness of cumulative evidence. randomized controlled trials (RCTs) involving 4473 patients were included for further analysis. ANH was associated with a 27% relative reduction in the incidence of allogeneic blood transfusions (RR = 0.73, 95% CI = 0.60 to 0.88; <i>p</i> = 0.0008) and a decrease in the volume of allogeneic red blood cell units transfused (MD = − 0.75 units, 95% CI = − 1.41 to − 0.08; <i>p</i> = 0.020). Fresh frozen plasma transfusion requirements were also significantly reduced (MD = − 0.21 units, 95% CI = − 0.39 to − 0.03; <i>p</i> = 0.0248), along with total blood loss (MD = − 64.35&#xa0;mL, 95% CI = − 114.57 to − 14.13; <i>p</i> = 0.012). However, chest tube drainage, surgical revision, and stroke incidence showed no significant differences between ANH and usual care. This meta-analysis demonstrates that ANH significantly reduces the need for allogeneic blood transfusions and improves outcomes such as red blood cell and fresh frozen plasma usage during cardiac surgery. The findings highlight ANH’s potential as an effective blood conservation strategy, though variability in outcomes and heterogeneity warrant further high-quality research to optimize its application in contemporary cardiac surgical practices.</p>