Economic growth and development and the factors affecting it have always been the main goals of economic policy makers. Early growth theories based on the two factors؛ capital and labor, could not explain clearly the difference between the level of per capita income and the rate of economic growth of countries. As a result, new theories have emerged and by relying on knowledge-based economics and measuring the amount of knowledge used in a country's products, indicators such as the index of economic complexity have achieved good results in this field. The purpose of this paper is, explain the role of economic complexity index along with other traditional growth variables in the economic growth of 13 MENAT selected countries in the years 2008-2017, using panel data and using the Generalized Movement Model (GMM). The software is Stata 16. Based on the results, the variables: government size, per physical capital formation and volume of trade with negative coefficients-16. 16,-0. 06 and0. 33, respectively, have a negative impact on the economic growth and human capital and economic complexity index with coefficients 0. 12 and 0. 074 have positive and significant impact on the economic growth of the studied countries. Therefore, increasing investment in training innovative and creative labor, expanding economic complexity and indicators can bring higher economic growth to the region. The low coefficient of economic complexity index in these countries indicates the lack of attention of these countries to the production of high-tech products.