Objective To evaluate the postoperative heart function of patients with acute anterior myocardial infarction (AMI) receiving emergency percutaneous coronary intervention (PCI) within 6-12 h of attack or selective PCI. Methods Seventy-seven patients wih AMI were divided into an emergency PCI group (30 cases) and a selective PCI group (47 cases). The patients in the emergency PCI group received emergency PCI within 6 to 12 hours after attack, the patients in the selective PCI group were treated by elective PCI (over 12 hours) after 7 to 10 days. LVEDd, LVEF, NT-proBNP and cardiac troponin I (CTNI) were monitored on the day of admission, every other day and 10 days later, then compared between the two groups. Results In the emergency PCI group, LVEDd at the time of admission and discharge had no significant difference (P > 0.05), while the LVEF decreased at discharge (P < 0.05). In the selective PCI group, the LVEDd increased and LVEF significantly decreased at discharge (P < 0.05). The differences of LVEDd and LVEF at admission and discharge were significantly different between the two groups (P < 0.05). The NT-proBNP and CTNI levels of the emergency PCI group were significantly lower than those of the selective PCI group (P < 0.05). Conclusions The heart function will decline in a short time in the patients with AMI undergoing emergency PCI within 6-12 h of attack or selective PCI, but it decreases more in the selective PCI group than in the emergency PCI group, which indicates that emergency PCI operation within 6-12 h of attack has positive effect on the cardiac function of AMI patients. The mechanism may be that emergency PCI operation can provide revascularization as soon as possible and save more survival myocardium.