Abstract: Economic integration between GCC and D-8 countries does not necessarily imply non-economic cooperation with rest of the world. Therefore, economic integration between these two groups of countries could be a key to their long-run economic development. This paper discusses a comparative analysis of selected economic indicators of the GCC and D-8 countries with European Union. The comparisons between the GCC-D-8 countries and EU indicate that manufacturing industries and agriculture in the GDPs show wide difference, but GDP growth rate, inflation rate and their average rates are not significantly different. The GCC and D-8 countrys` mesmerizing consumer market, which is larger than that of EU, the investment ardor of foreign suitors. Labor absorbing capacity of the GCC and D-8 country`s economy is higher than that of EU economy. Apart from petroleum, to establish a common policy for other products within GCC and D-8 countries will not necessarily impede GCC countries` trade relationship with others as well as their export earnings. Thus, there is a potential opportunity to establish a common market within GCC and D-8 countries, which could be expanded in other OIC member countries. Some policies and issues of common economy within GCC and D-8 countries and its effectiveness for sustained economic growth and trade balances to meet emerging challenges also are explored.