Background and aims: This study is to compare the short-term and long-term mortality in patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation acute coronary syndrome (NSTE-ACS) after percutaneous coronary intervention (PCI). Methods and results: A total of 266 STEMI patients and 140 NSTE-ACS patients received PCI. Patients were followed up by telephone or at medical record or case statistics center and were followed up for 4 years. Descriptive statistics and multivariate survival analyses were employed to compare the mortality in STEMI and NSTE-ACS. All statistical analyses were performed by SPSS19.0 software package. NSTE-ACS patients had significantly higher clinical and angiographic risk profiles at baseline. During the 4-year follow-up, all-cause mortality in STEMI was significantly higher than that in NSTE-ACS after coronary stent placement (HR 1.496, 95% CI 1.019-2.197). In a landmark analysis no difference was seen in all-cause mortality for both STEMI and NSTE-ACS between 6 month and 4 years of follow-up (HR 1.173, 95% CI 0.758-1.813). Conclusions: Patients with STEMI have a worse long-term prognosis compared to patients with NSTE-ACS after PCI, due to higher short-term mortality. However, NSTE-ACS patients have a worse long-term survival after 6 months.