Purpose: The objective of this study was to analyze the clinical characteristics of patients younger than 35 years with acute myocardial infarction (AMI). Methods: A total of 117 patients younger than 35 years with AMI admitted to the hospital during the recent 10 years were chosen, and 355 patients older than 65 years with AMI served as a control group. The case history, clinical data, coronary angiography and prognosis of the patients were analyzed and compared. Results: Among the younger patients with AMI, men (96.6%) and those smoking cigarettes (66.7%) account for the majority. ST-segment elevation (69.2%) and anterior wall infarction (43.6%) were more prevalent in the younger patients than in the older patients. Compared with the older patients, the younger patients had a higher level of low-density lipoprotein cholesterol (2.93 +/- 1.48 versus 2.35 +/- 1.21, P = 0.0428) and higher left ventricular ejection fraction (59.82 +/- 10.86 versus 48.31 +/- 12.48, P = 0.0396). Coronary angiography data showed that most of the younger patients were characteristic of having single-vessel lesion (66.7%), left anterior descending artery lesion (69.3%) and coronary artery spasm more than the older patients (6.8% versus 0.56%, P = 0.0001). In addition, the in-hospital mortality, and the prognosis after 1 and 12 months in the younger patients were comparatively better. Conclusions: The main risk factors for young adults aged,35 years with AMI include cigarette smoking, hyperlipidemia and family history of coronary artery disease, and smoking cessation and lifestyle improvement are important considerations for the prevention of this disease in this population.