OBJECTIVE: The objective was to study patients' interpretations, thoughts, and actions after symptom onset in acute coronary syndrome (ACS) in total and in relation to gender, age, history of coronary artery disease, type of syndrome, and residential area and its influence on prehospital delay. SETTING: We performed a national survey comprising intensive cardiac care units at 11 hospitals in Sweden. METHOD: A total of 1,939 patients with diagnosed ACS and symptom onset outside hospital completed a questionnaire containing standardized questions within 3 days after admission. RESULTS: Three-quarters of the patients interpreted their symptoms as cardiac in origin, and the most common reason was that they knew someone who had had an acute myocardial infarction. The majority contacted a family member, whereas only 3% directly called for an ambulance. Interpreting the symptoms as cardiac in origin and severe pain were major reasons for deciding to seek medical care. Approaching someone after symptom onset and the belief that the symptoms were cardiac in origin were factors associated with a shorter prehospital delay, whereas taking medication to relieve pain resulted in the opposite. The reaction pattern was influenced by gender, age, a history of coronary artery disease, and the type of ACS, but to a lesser extent by residential area. CONCLUSIONS: Interpreting symptoms as cardiac in origin and approaching someone after symptom onset were major reasons for a shorter prehospital delay in ACS.