Coronary artery ectasia (CAE) is defined as the dilation of a segment of a coronary vessel to at least 1.5 times the diameter of its normal adjacent segment. Mean platelet volume (MPV) plays a role in acute coronary syndromes, with high MPV correlating to poor prognosis for acute thrombotic events and CAE. Several studies investigated the relationship between MPV and CAE, resulting in conflicting results. These results led us to systematically review all studies investigating the relationship between MPV and ectatic heart diseases by performing a meta-analysis study in order to report a unified result. This meta-analysis study investigated all case-control articles examining the relationship between MPV and CAE. All studies in the following databases published until January 31, 2018, were investigated: Science Direct, Scopus, PubMed, Google Scholar, and Web of Science. Following a quality control evaluation, 14 articles, all of which were published following studies performed in Turkey from 2007 to 2016, met the criteria for study inclusion. After pooling the results from all of the articles, a total standardized mean difference (SMD) value of 0.584 (95% CI, 0.219, 0.95) was obtained using the D+L pooled SMD, indicating a significant difference (P=0.002) between the two groups, with higher MPV values in ectatic patients when comparing to healthy individuals. Therefore, increased MPV levels were significantly related to CAE, suggesting that platelets, with their inflammatory and thrombotic activities, play a role in this disease. Therefore, anti-platelet and anti-inflammatory therapies may be effective in treating CAE.