Background: Few studies have qualitatively explored their thoughts and actions after symptom onset to seek medical assistance in patients with acute myocardial infarction (AMI) in Korea. Objectives: This study was conducted to identify their decision-making behaviors during the period between onset of symptoms and treatment seeking, and to examine influencing factors on delayed presentation to hospital among patients with the first-time AMI. Methods: A total of 193 patients were conveniently recruited from a coronary care unit between November 2007 and June 2008. After approval of institutional review board, semi-structured interviews were conducted by principal investigator during their stays in the hospital following coronary intervention. Results: The delay time was 12 hours (짹 107.9) and mean age was 63 짹 12.5 years (ranged 29-89). The 70% (n=136) and 30% (n=57) of the sample were male and female respectively. The majority (75%) did not recognize their symptoms as cardiac in origin and 61% thought their symptoms were not serious. The actions after symptom experience were visiting a local clinic or hospital (49%), bearing and waiting (23%), self-medication or visit pharmacy to have pills (21%), and contacting their family (17%). The reasons for delay were no recognition of symptoms as serious, attribution to their weakened body strength or aging, and attribution to indigestion, severe flu or muscle pain. Logistic regression analysis showed that patients experienced symptoms as progressive or intermittent development, experienced symptoms at home, and not recognized as cardiac in origin or serious problem were significantly associated with delayed presentation > 12 hours (p< 0.05). Conclusions: This finding indicated a lack of knowledge about symptoms of AMI and appropriate decisions and actions to seek medical care when an AMI occurred. Public education and individual counseling should focus on the signs and symptoms of AMI and action guidelines following chest discomfort.