Abstract Acute myocardial infarction (AMI) is less frequent in young individuals (≤ 45 years) than in older ones (> 45 years). Young AMI patients differ from older AMI patients in different ways. This article aims to assess the differences between young and older AMI patients. A search was made in the database of Cochrane Library, PubMed, BioMed Central and Embase, sence their establishment to December 2016, using the key words: risk factors, clinical characteristics, acute myocardial infarction and young. Meta-analysis was performed by using the Review Manager 5.3 software, pooled odds ratios and 95% confidence intervals were used to assess the strength of differences. Eight studies with fairly quality, enrolling 13,358 patients in the analysis. Compared with older AMI patients, young AMI patients had a higher rate of smoking and obesity (OR = 2.71,95%CI:1.87 to 3.92; OR = 1.76,95%CI:1.13 to 2.74), higher rate of family history of coronary artery disease and alcohol consumption (OR = 2.36,95%CI:1.22 to 4.59; OR = 1.76,95%CI:1.04 to 2.97). Moreover, Young AMI patients had a lower rate of hypertension and diabetes mellitus (OR = 0.52,95%CI:0.37 to 0.73; OR = 0.58,95%CI:0.50 to 0.67). No significant differences were observed in hyperlipidemia, a subgroup data-analysis showed a higher total cholesterol, triglyceride lipase, and low-density lipoprotein levels (p < 0.05), and lower levels of high-density lipoprotein (p < 0.01) in young AMI patients. Smoking, family history of coronary artery disease, obesity and alcohol consumption are the most main risk factors of AMI among young individuals, and young AMI patients have better prognosis than older ones.