Depression following Myocardial Infarction (MI) is a common disorder with a negative effect on prognosis of cardiac patients. One of the therapeutic methods of depression in cardiac patients is cognitive-behavioral technique. The aim of the present study was to assess the efficacy of Eye Movement Desensitization and Reprocessing (EMDR) on depression in patients with Myocardial Infarction (MI) in a 12-month follow up. It was a quasi-experimental study, which was performed on patients with MI in Qazvin in year 2013. 60 patients, who were suffering from MI were selected through convenient sampling and based on Beck’s depression questionnaire; they were randomly divided into two experimental and control groups. EMDR therapeutic method was performed in three sessions in the experimental group. The control group received no intervention. Data collection on depressive symptoms was done before treatment, after treatment and in a 12-month follow up and they were analyzed by using descriptive statistics, repeated measures ANOVA, chi-square and SPSS 17 software. Depressive symptoms mean in the experimental group before and after intervention and in a 12-month follow up was 27.26±6.41, 11.76±3.71 and 8.5±2.52 respectively; repeated measures ANOVA showed significant statistical difference (p< 0.001). Depressive symptoms mean in the control group before and after intervention was 24.53±5.81 and 31.66±6.09 respectively, it showed significant difference by using paired t-test (p< 0.001). The EMDR is an efficient method for treating and reducing depression in patients with MI. Critical care nurses can use this new and effective method for treating depression.