Ischemic heart disease (IHD) is the most common cause of death around the world. Nowadays Platelet counts (PC) and volumetric platelet indices are available routinely in most laboratories and reflect the level of mobility and production of platelets. It seems that the excessive flexibility and size of the platelets and their local activation have correlation with extent of ischemic heart disease. So our objective is the study of platelet indices in ischemic heart disease. This non-randomized prospective study was performed on 245 patients with ischemic heart disease, who underwent the coronary angiography. The patients were divided into four groups: stable angina, unstable angina, acute myocardial infarction and control group; and then platelet indices, including the platelet counts (PC), the average platelet volume (MPV), the Platelet Distribution Width (PDW) and plateletcrit (PCT) in each group with the extent of coronary disease were compared based on an Syntax Score system and observational methods. The average ages of the patients were 57 years and 65% of them were male and the rest were female. A significant difference is exists between indices in all three groups compared to the control that this difference was related to gender and the type of the coronary artery involvement. However, only in infarction group, PDW in different disease intensities was significantly different. In this study, unlike many of the previous studies no relationship was found between the MPV with the extent of coronary disease.