Trade in services has been growing in recent decades especially among developing countries. Services export can improve the trade balance, expand employment, boost economic growth and also support the development of the merchandise sector. The main object of this paper is to study the competitiveness by Revealed Comparative Advantage (RCA) index and to evaluate the main factors affecting the export of services among OIC member countries by panel data method. Findings of RCA index show that the comparative advantage of travel and transportation services export among these countries has increased and percentage of countries which have RCA less than unit has increased. The factors such as GDP per capita, real effective exchange rates, foreign investment inflow, and communication infrastructure have significant and positive effects on export services. The variables such as inflation and institutional index reduce the services export. Furthermore, the membership of these countries in regional blocks, ECO and D8, has increased the export of services. Therefore, policy makers in public and private sectors should plan for development of services exports by consideration of main factors affecting and comparative advantages.
