Abstract： Objective To analyze the correlation between the complication by community-acquired pneumonia(CAP)and the short-term prognosis in hospitalized acute myocardial infarction(AMI)patients.Methods Five thousand five hundred and twenty-four AMI patients hospitalized in the PLA General Hospital from January 1993 to December 2009 were enrolled for clinical data,incidence of complications and 30-day mortality.The data from patients with and without CAP complications were compared.Multivariate logistic regression analysis was employed to assess the impact of CAP on the short-term prognosis of these patients.Results In all 5 524 AMI patients studied,477 cases of CAP was found(8.6％).In comparison with those without CAP complication,these patients had higher age(74.3± 6.5 vs.67.8± 4.5).The incidence of comorbidities[including old myocardial infarction(20.8％ vs.11.5％),hypertension(54.3％ vs.48.9％),diabetic mellitus(32.7％ vs.22.6％),cerebral-vascular disease(8.2％ vs.3.5％),chronic renal dysfunction(10.5％ vs.3.0％)],and complications[including arrhythmia(8.8％ vs.4.6％),gastrointestinal bleeding(5.0％ vs.0.8％)and shock(8.6％ vs.3.1％)]were all significantly higher,and hyperlipidemia(18.9％ vs.30.6％)was significantly lower(P＜0.05 or P＜0.01)in CAP complicated patients.The 30-day mortality was also significantly higher(32.1％ vs.9.7％,P＜0.01).Multivariate logistic regression analysis identified CAP and chronic renal dysfunction as an independent predictor of short-term mortality[odds ratio(OR)of CAP 3.693,95 ％ confidence interval(95 ％CI)2.340～5.829,P＜ 0.01; OR of chronic renal dysfunction 12.608,95％CI 4.448 ～ 35.739,P＜0.01].Conclusions The incidence of CAP complication was higher in AMI patients with higher age.CAP complicated patients were more likely to develop comorbidities/complications,and had higher short-term mortality.CAP was an independent risk factor of short-term mortality.