Aim To investigate the relationship between red cell distribution width(RDW) level and risk of complication in acute myocardial infarction(AMI) patients;to compare the correlation of RDW with N-terminal pro-brain natriuretic peptide(NT-proBNP),cardiac troponin I(cTnI) and high sensitivity C-reactive protein(hs-CRP). Methods 200 consecutive AMI patients were classified into complication group(n=145)or complication-free group(n=55) according to the presence or absence of new-onset symptomatic heart failure,arrhythmia or cardiac shock.Patients were divided into quartiles based on RDW value(≤12.8%,12.9%～13.8%,13.9%～14.7%,≥14.8%,n=50 in each quartile),and odds ratio(OR) of incident complication was calculated by using Logistic regression.Correlation of RDW with NT-proBNP,cTnI and hs-CRP was compared by Spearman rank correlation analysis. Results RDW levels in complication group was significantly higher than that in complication-free group(14.50%±0.97% vs 12.90%±0.85%,P><0.05).RDW levels of AMI patients were positively associated with complication risk,after adjustment for estimated glomerular filtration rate,serum ferrum,left ventricular end-diastolic dimension,left ventricular ejection fraction,and plasma NT-proBNP,cTnI and hs-CRP levels,the highest RDW quartile entailed 1.96 times greater risk for complication than the lowest quartile(95% CI 1.34～2.79,P><0.05).Correlation intensity order of RDW was NT-proBNP>cTnI>hs-CRP(rs=0.31,0.29 and 0.21 respectively,all P><0.05). Conclusion Higher RDW is closely associated with increased risk of AMI complication and elevated plasma NT-proBNP and cTnI level.