This study evaluates whether an initial blood glucose level is similarly predictive of injury severity and outcome as admission lactate in trauma patients. Between February 2004 and June 2005, we prospectively compared patients with presenting blood sugars of < or =150 mg/dL (LBS) with those with blood sugars >150 mg/dL (HBS). Fifty patients had BS above 150 mg/dL, whereas 176 patients were < or = 150 mg/dL. These groups had similar demographics except for age. Injury Severity Score (ISS) of > or = 15 was seen in 56.0 per cent of HBS patients versus 28.4 per cent of LBS patients (P = 0.0006). HBS patients had similar infection rates (12.0% HBS vs. 5.7% LBS, P = 0.13) but a higher mortality (30.0% HBS vs. 5.7% LBS, P < 0.0001). There was a linear relationship between ISS and BS (r2 = 0.18, P < 0.0001) and ISS and lactate (r2 = 0.17, P < 0.0001). Blood sugar trended with the lactate (r = 0.25, P = 0.0001). Hyperglycemic patients were more severely injured with higher mortality. BS correlated with lactate, and because it is easily obtainable, it may serve as a readily available predictor of injury severity and prognosis.