Abstract: This study aims to criticize and debate the Economic Islamicity (EI) index that was developed by Rehman and Askari. We believe that the design of this index has fallen into a theoretical black hole by assuming specific areas to measure the EI as well as choosing some unfair and biased indicators to develop this EI index. Surprisingly, their study concluded that the top countries that adhere to Islamic ideologies and teachings in both economic achievement and social values are Ireland, Denmark, Luxembourg, Sweden and the United Kingdom. The first Muslim country is Malaysia ranking at 33 while the only Arab state in the top 50 is Kuwait at the rank of 42. We used the methodological criticism in this study to critically assess, analyze and review this EI index. The main findings of this research effort are that the study of Rehman and Askari does not conform to the Maqasid Shariah which serves to guide the economic, social, political and cultural aspects of Islamic societies. Moreover, the study excluded the 5 main pillars of Islam when they were building their measures and proxies of EI index. Despite the researchers introducing and using the index as an Islamicity index, Islam is not part of the criteria or forming the standards. Therefore, the EI index introduced by their study is claimed to be unreliable, inaccurate and does not reflect the economic Islamicity whatsoever as discussed and explained in this research effort. The main implication of this study is to shed some light that may lead to overcome the theoretical and practical lapses existing in the EI index. Hopefully, reconsidering and criticizing the EI index would enhance the validity and applicability of this index.