Background: In most countries of the Western world there have been positive reductions in incidence of cardiovascular diseases in the past decades, among both men and women, but still mortality due to these disease groups are very high. Many studies about myocardial infarction have shown that depression after an event is related to poor medical outcomes from the disease. This means prolonged disability events of angina, arrhythmias, re-hospitalization and increased rate of mortality. In post myocardial infarction patients, depression is a major cause of both short and long term mortality. Aim: The aim of this study was to examine the scientific literature by a systematic review in order to find evidence based knowledge about the benefit of physical activity as a tool to reduce depression in patients with coronary artery event. Method: Three databases were searched (Pubmed, CINHAL, Cochrane) systematically and all articles that met inclusion criteria were examined and graded according to the criteria “Grading quality of evidence and strength of recommendations” by Atkins. A special protocol was designed further from AMSTAR by Beverley, for systematic review with and without the meta-analysis study. Results: It was evident that scientific reports fitting to the area was scarce showing that the area of interest was fairly new. Finally ten studies were included in this study, one meta-analysis, five randomized controlled trail and four clinical trials. The results showed low to moderate evidence for the use of high, moderate and low level of exercise as a tool to reduce depression in post coronary artery event patients. Conclusion: The following study concluded that, exercise shows positive effects to reduce the level of depression among coronary artery event patients.