BACKGROUND Acute myocardial infarction (AMI) is an incredibly destructive disease when it occurs in a young patient. Thus, the investigation of the disease presentation and treatment options seem to be particularly important in young patients with AMI. OBJECTIVE The study objective was to investigate the differences between young and older patients diag-nosed with AMI in terms of clinical characteristics and treatment strategies. METHODS The patient data comes from the National Registry of Procedures of Invasive Cardiology (ORPKI). Between 2014 and 2017, data of more than 230 000 patients with a diagnosis of AMI were collected in that registry. Young patients were defined as under 40 years old. RESULTS Young patients with AMI (n = 3208, 1.3%) compared with older patients with AMI were more often men (86.3% vs. 65.8%; P <0.001) with higher body weight (mean 85.9 vs. 79.7 kg; P <0.001). Typical risk factors of coronary heart disease were less frequent in younger patients than in older patients. However, in the under-40 group, there was a significantly higher number of current smokers (37.5% vs. 23.0%; P <0.001). Young patients with AMI were more often diagnosed with ST-segment elevation myocardial infarction (STEMI; 62.0% vs. 50.0%; P <0.001). Moreover, they had more frequently non-significant ste-nosis in coronary arteries diagnosed (14.4% vs. 6.8%; P <0.001). The left anterior descending artery was more frequently an infarct-related artery in young patients (51.3% vs. 36.3%; P <0.001). Bioresorbable vascular scaffolds were more commonly implanted in young patients with AMI than in the older ones (5.6% vs. 0.9%; P <0.001). The relative number of AMI in the young patients increased from 1.20% in 2014 to 1.43% in 2017. CONCLUSIONS Smoking is the most common risk factor in young adults. The relative number of AMI in young patients is growing.