Given the post-9/11 climate of global uncertainty, suspicion, hostility, and fear, interest in the relationship between religion and economics, politics, and social behavior has been rekindled. In particular, there has been considerable attention afforded to the impact of religion on economic, social, and political development and vice versa. However, before the impact of religion on economic performance or the impact of economic performance on religion can be examined, one should first ascertain the religiosity of a country. In this case, “how Islamic are Islamic countries?” or “what is their degree of ‘Islamicity?’” In this paper, we assess, on a very preliminary basis, the adherence of Islamic countries to Islamic economic teachings and develop an Economic IslamicityIndex (EI2) to assess the extent that self-declared Islamic countries adhere to Islamic doctrines and teachings. We do this by measuring 208 countries’ adherence to Islamic Economic principles using as proxies 113 measurable variables