Background <p>Patients in intensive care units (ICUs) commonly experience stress hyperglycemia, which is linked with poor cardiovascular outcomes and high hospital mortality. The stress hyperglycemia ratio (SHR) may serve as a critical risk factor for acute kidney injury (AKI) in specific individuals. Nevertheless, the link between SHR and hospital mortality and AKI in transfused patients is unclarified.</p> Methods <p>Participants were non-consecutively sourced from the MIMIC-IV database and allocated into quartiles based on SHR. Hospital mortality and AKI incidence were the endpoints. The association of SHR with hospital mortality and AKI was examined through restricted cubic splines and Cox models. Endpoint differences across quartiles were estimated using the Kaplan–Meier method.</p> Results <p>1381 patients were enrolled, with 59% of males. AKI incidence was 81.0% and in-hospital death was 9.8%. Cox analyses revealed a notable link of SHR with hospital death in critically ill transfused patients, while the correlation with AKI was comparatively weak. However, it also showed a notable link of SHR with hospital death and AKI risk of non-diabetes. Restricted cubic spline models uncovered a linear connection between SHR and AKI risk and a nonlinear connection between SHR and in-hospital death. After adjustment of variables in Model 3, it showed a nonlinear relationship of SHR with in-hospital death and AKI risk of non-diabetes. Furthermore, in-hospital survival considerably varied in transfused patients with different SHR levels.</p> Conclusions <p>SHR independently predicts hospital mortality in critically ill transfused patients. Among non-diabetes, SHR is significantly associated with hospital mortality and AKI risk. However, larger prospective studies are warranted to check the causality.</p>