Introduction Coronary artery disease (CAD) remains a leading cause of morbidity and mortality globally, with an increasing prevalence of acute myocardial infarction (AMI) among younger populations. Despite this rising trend, there are limited data from Myanmar on the clinical profile and associated risk factors for premature CAD in young adults. This study aims to investigate the clinical characteristics and predisposing risk factors for AMI in individuals aged 40 years and below, contributing to a better understanding of disease patterns in this population. Methods A cross-sectional descriptive study was conducted at the coronary care unit of Yangon General Hospital over a 12-month period from January 1, 2019, to December 31, 2019. A total of 59 young adults, diagnosed with AMI based on the Fourth Universal Definition of Myocardial Infarction, were included. Clinical data, laboratory investigations, and demographic characteristics were collected and analyzed. Results Among the 59 participants, 46 (78%) were male, and smoking was prevalent in 45 (76.3%) cases. Dyslipidemia was common, with 46 (77.9%) exhibiting low high-density lipoprotein (HDL) cholesterol levels and 27 (45.8%) having elevated total cholesterol. Hypertension was observed in 31 (52.5%) patients, and 32 (54.2%) reported a family history of premature atherosclerotic cardiovascular disease. Furthermore, 28 (47.5%) of the cohort were classified as overweight, and 26 (44.1%) demonstrated low levels of physical activity. Chest pain was universally reported by all 59 (100%) patients as the presenting symptom. ST-segment elevation myocardial infarction (STEMI) was the predominant type, affecting 47 (79.6%) patients, with anterior wall involvement in 36 (61%) cases. Conclusion The findings of this study reveal that AMI in young adults is more prevalent among males, with smoking and dyslipidemia being the most significant risk factors. The high prevalence of low physical activity, hypertension, and overweight status further underscores the need for early lifestyle interventions. These results can be directly applied to clinical practice and public health policy in Myanmar by prioritizing smoking cessation programs, improving dyslipidemia management, and promoting physical activity in young populations. Additionally, this study provides a foundation for further research to explore more specific risk factors and paves the way for broader studies focusing on young AMI cases in Myanmar.