Aim Investigate whether the Geriatric Nutritional Risk Index (GNRI), a combined nutritional score based on serum albumin levels and the body mass index (BMI), was associated with mortality in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). Methods 309 consecutive patients with STEMI undergoing PCI were prospectively enrolled. Results Patients were then divided into two groups according to GNRI ROC:GNRI≥94 or GNRI＜94 were assigned a GNRI score of 0 or 1, respectively. Of the 309 STEMI patients, 24 (7.74%) died in the hospital, and 15 (4.83%) died during long-term follow-up (median follow-up time, 19.5(3～36) months). Compared with patients with a GNRI of 0, patients with a GNRI of 1 had significantly higher in-hospital (16.7% vs 4.4%; P<0.001) and long-term follow-up (23.8% vs 8.4%, P<0.001) mortality rates. GNRI(HR 2.9,5%CI 1.038 to 4.004, P=0.039) was a significant independent predictor of mortality in patients with STEMI undergoing PCI. Moreover, cumulative survival was significantly lower for patients with a GNRI of 1 compared with patients with a GNRI of 0 (76.2% vs 91.6%, log-rank P<0.001). Conclusion GNRI appears useful for the risk stratification of STEMI patients undergoing PCI.