Myocardial infarction (MI) or acute myocardial infarction(AMI) is known as heart attack. MI occurs when blood stops flowing properly to a part of the heart. MI occurred when one of the coronary arteries develops a blockage due to an unstable buildup of with blood, cholesterol and fat. This study aimed to determine the time interval between the onset of clinical symptoms and receiving streptokinase inpatients with acute myocardial infarction (AMI) at Amir Hospital in Zabol city in 2013. This was a cross-sectional-descriptive study. In total 72 patients were selected from all patients with chest pain and who referred to the emergency of Amir Hospital during 2013 in Zabol located in southeast of Iran. All patients were diagnosed with AMI. The instrument used for data collection was a questionnaire including demographic characteristics, record of exact location of infarction, ECG, the time of patients' arrival to the emergency department (ED), and the time of receiving streptokinase. According to the obtained results of this study, the mean of onset to call, call to door, and door to needle times were 269.29±197.33, 34.02±12.32, and 96.33±49.95, respectively. The comparison of onset to call, and call to door and age, education and place of residence variables showed that there was a significant difference between these variables. In addition, the comparison of door to needle time and age, sex, education and place of residence variables showed that there was no significant difference between these variables. Delay in treatment of patients with STEM I is caused as a result of several factors including rate of patient's awareness and emergency status. We need to provide opportunities to treatment of MI by emergency and outpatient centers. To reducing in-hospital delay, we must teach physicians and emergency personnel to rapid diagnosis ofMI.