The re-establishment of independence of the Republic of Estonia in 1992 went on in the conditions of transitioning of the planned economy to the environment of open conditions or market economy. Transition to the political independence took place in the situation, when certain economic independence was achieved in the terms of intensive decay of the Soviet system of planned economy. The period after regaining independence has been time for recreation and reform of foreign trade relationships. Estonian economic system is vulnerable due to its small size and openness. As far international trade has drastic impact to the economic growth and prosperity, separate research of static effects of free trade on Estonia as a small economic system is performed in the given paper. Author will not make binary decision about the usefulness or uselessness of the WTO membership. The aim is to determine different ways of affection that WTO may impose on the economy of Estonia. Author has concluded 3 main areas of impact of WTO accession using comparative empirical data analysis to determine the influence on a small country with intensively open economy.