Objective This study was undertaken to determine the relationship between red cell distribution width (RDW) and short-term outcomes in acute coronary syndrome (ACS) in a Chinese population. Methods and Patients A total of 1,654 patients with ACS on admission were divided into four groups according to quartiles of baseline RDW. The relationships between RDW and one-month cardiac mortality as well as heart failure and recurrent infarction were assessed. Results Higher RDW values were associated with increased one-month cardiac mortality (quartile 1: 0.2%; quartile 2: 0.6%; quartile 3: 3.3%; quartile 4: 8.1%; p<0.001) and one-month heart failure and recurrent infarction (quartile 1: 2.1%; quartile 2: 2.7%; quartile 3: 3.6%; quartile 4: 15.2%; p<0.001). Logistic regression analysis revealed that RDW independently predicted for cardiac mortality (OR: 2.116, 95% CI: 1.427-3.137, p<0.001) and heart failure and recurrent infarction (OR: 2.134, 95% CI: 1.602-2.844, p<0.001) during a one-month follow-up in patients with ACS. Conclusion The present study indicates that elevated RDW could predict an increased risk of short-term adverse outcomes in patients with ACS.