Abstract Objective Critical illness is often accompanied by elevated blood glucose, which generally correlates with increased morbidity and mortality. Prehospital blood glucose (PBG) level might be a useful and easy‐to‐perform tool for risk assessment in emergency medicine. This retrospective single‐center cohort study was designed to analyze the association of prehospital glucose measurements with hospitalization rate and in‐hospital mortality. Methods Records of 970 patients admitted to a university hospital by an emergency physician were analyzed. Patients with a PBG ≥140 mg/dL (G1, n = 394, equal to 7.8 mmol/L) were compared with patients with a PBG