Background: Young and middle-aged men are the most important group to manage their lifestyle factors to prevent cardiovascular diseases (CVD). Interpretation of acute myocardial infarction (AMI) symptoms is clearly subjective and may vary with multidimensional aspects. Purpose: This study was to identify the perceptions of lifestyle risk factors of having AMI and the interpretations of their acute symptoms in young and middle-aged male patients with first-time AMI. Methods: The study design was a triangulation study. A total of 120 male patients < 65 years of age were individually interviewed using semi-structured questionnaire after the approval of institutional review board, 2008-2009. The quantitative and qualitative data were analyzed using SPSS program and qualitative content analysis, respectively. Results: Pre-hospital delay > 3 hours was shown in the 58.3% (n=70) of the sample and was significantly associated with low socio-economic status (p<.05). About 22% answered that their chief complaint was not chest pain at admission and the 63.3% had no recognition about their symptoms as cardiac in origin. The mean number of risk factors was 3.9짹1.8 out of 11 when lifestyle and psychosocial factors included. From the qualitative data of 70 patients delayed > 3 hours, six major themes were emerged by personal-cognitive, socio-cultural, and contextual factors: 1) self-appraisal for their symptoms: denial of seriousness or optimism bias, rationalizing the reason of their symptoms; 2) lack of recognition of AMI: thinking never have AMI, convincing in good physical health; 3) lack of knowledge of AMI symptoms: attribution their symptoms to chronic disease, low knowledge of AMI symptoms and actions, misconception for atypical and intermittent symptoms; 4) underestimation of risk of having AMI: justifying their unhealthy lifestyle as a means to decrease their stress; 5) socio-cultural barriers: men���s living in Korea, feeling the shame of 119 use and troubling others; 6) contextual barriers: economical burden, lack of social supports, worry about medical expenses in visiting emergency department, anxiety about treatment gap for holiday attack. Conclusions: Health care providers should concern these factors and themes in designing educational intervention to make their lifestyle changes and to facilitate their prompt decision to seek care for men in productive age at risk for CVD.