This paper summarizes the present knowledge of delay time in suspected acute myocardial infarction. More than 50% of deaths in acute myocardial infarction occur outside of the hospital setting. Recent experiences indicate that early and even late mortality can be dramatically reduced by intervention in the early phase. This points up the importance of bringing patients with suspected acute myocardial infarction to the hospital as early in the course of MI as possible. The predominating cause of delay is the time it takes for the patient to decide to go to hospital regardless of a previous history of cardiovascular disease. Patients arriving in hospital in later stages of MI are at a very high risk of mortality. Therefore one of the most important problems to be resolved is how to reduce delay time in suspected acute myocardial infarction. Such efforts have been surprisingly few. Limited experiences indicate that public education can reduce delay time dramatically.