Abstract INTRODUCTION: Depression is common amongst post-myocardial infarction (MI) patients and it has been associated with adverse clinical events in these patients. Post-MI depression has also been shown to be an independent risk factor for mortality. However, many questions about risk factors of post-MI depression remain unanswered. The purpose of this study was to identify the medical and demographic predictors of post-MI depression, in so far these are routinely available during MI hospitalization. methods: 176 consecutive patients admitted to the CCU wards following MI were selected based on the inclusion and exclusion criteria. Baseline measures were conducted during hospitalization using a standardized history that included questions about demographic characteristics and medical information, and all patients were underwent a physical examination. Severity of MI index was assessed by a cardiologist using the Killip Class. Also CPK levels were measured on admission and over the 2 subsequent days as additional measures of the severity of MI. The diagnosis of depression (including major and minor depression) at three months after MI was assessed using a standardized, semistructured research interview by a psychiatrist and a clinical psychologist. This interview provided DSM-IV diagnoses based on the patients’ psychiatric symptoms. results: The findings showed that 46/6% suffered from post-MI depression three months following MI. In multivariable analysis, beta-blocker (OR 2.987; CI 1.254-7.116), history of depressive disorders (OR 2.838; CI 1.271-6.340), log max CPK (creatinine phosphokinase value) (OR 2.410; CI 1.075-5.404), and age <60 (OR 2.652; CI 1.061-6.626) were factors significantly associated with post-MI depression. This predictive model also yielded 74.4% maximum predictive efficiency with 67.1% sensitivity and 80.9% specificity rates respectively, for differentiating those with and those without high risk for developing post-MI depression. CONCLUSIONS: Beta-blocker, history of depressive disorders, log max CPK (creatinine phosphokinase value), and age comprise demographic and medical predictors for post-MI depressive symptoms. Thus, considering the above model, clinicians may able to identify MI patients with a high risk for subsequent development of depression so that these patients may be targeted for screening and potentially for psychosocial intervention. The association found between depression and creatinine phosphokinase (CPK) value begs the questions why two seemingly unrelated conditions should be related, and what mediators or common biological pathways could link the two phenomena. Keywords: Depression, myocardial infarction, demographic and medical predictors.