Although the goal of all regional organizations is to strengthen cooperation between member states, in some cases there are apparent or hidden rivalries in minor or major levels, which sometimes leads to stagnation and inefficiency of the regional organization and hinders effective cooperation. The need for cooperation in South West Asia to benefit all developing countries in the region became the main driver for the foundation of the Economic Cooperation Organisation (ECO) in 1985. This study aimed to identify the areas of rivalries among the member states of this organization resulting lack of cooperation and success, from a political geography and geopolitics point of view. Contexts of rivalries classified into four political, economic, cultural, and geopolitical factors containing eighteen sub-variables. The results showed geopolitical, political, cultural factors, and economic factors respectively have a positive and significant effect on rivalries in ECO