Primary spontaneous coronary artery dissection is an unusual occurrence. There have been less than 150 cases reported in world literature. This process frequently occurs in relatively young women, particularly in the peripartum or early postpartum period. This article reports the clinical course of one patient with primary spontaneous left main coronary artery dissection who was treated with coronary artery bypass grafting. To our knowledge, it is the second case to be treated with the use of left internal mammary artery.