This thesis investigates the relation between trade and convergence for Turkey and EU-15 in the period 1980-2008. The countries and time period are selected because Turkey has intensive trade relation with EU-15, and these economies had experienced conversion in their economic structures and adopted liberal economic policies, as well as liberal trade policies in this period. Using panel data methods two equations are estimated / an income dispersion equation for the impact of bilateral trade on per capita income differences and a gravity model of trade for the impact of per capita income differences on bilateral trade. Overall findings of this study give strong evidence for the hypothesis that trade causes convergence, whereas weaker support for the thesis that convergence causes trade.