One of the key issues among those suffering from acute coronary syndrome is the treatment and caring of them. The present research seeks to study the effectiveness of scenario-based education on the performance of the nurses in caring for the patients with acute coronary syndrome in the critical cardiac care unit. A semi-empirical research using pre-test and post-test with the control group was conducted on some 80 nurses of the critical cardiac care unit of Urmia’s therapeutic-educational centers. First, Seyed Al-Shohada and Ayat Allah Taleghani hospitals were first divided into the control and intervention centers. 40 nurses from Seyed Al-Shohada hospital and 40 from Ayat Allah Taleghani hospital were randomly placed in the intervention and control group respectively. During the research, 6 subjects were removed from the study and we had finally 38 people in the intervention group and 36 in the control group. The tools used for data analysis were divided into two parts: first, the demographic features, and secondly, the author-made checklist composed of 38 statements in caring for the patients with acute coronary syndrome. In the first step, the performance of all the participants in the three working shifts in the morning, afternoon and night was studied and their average performance scores were calculated in three shifts. In the intervention phase, the researcher delivered three two-hour speeches for the control group and eight two-hour scenario-based speeches in the intervention group on the cares and nursing performances for the patients suffering from acute coronary syndrome. One month after the intervention, the performance of the participating nurses in three different working shifts was measured and the average score of their performance was calculated for three shifts. The data was analyzed by SPSS v.15, chi-square, independent T, and paired test. As the results indicated, the average score of the nurses before the scenario-based training for the intervention and control group was 20.63 ± 2.13 and 21.44 ± 2.48 respectively (p = 0.150). After scenario-based training, the average performance score of the nurses for the intervention and control group was 24.32 ± 3.78 and 20.38 ± 3.32 respectively (p = 0.0001). Utilizing modern educational methods such as scenario-based learning can have a significant influence on enhancing the knowledge and performance of the nurses about their treatment with patients suffering from acute coronary syndrome.