This study aims to find out the impacts of international trading activities of firms on the their capital structure and profitability by using panel data analysis of the manufacturing companies listed in Istanbul Stock Exchange (ISE) for the period of 2009–2014. For this purpose we analyzed 107 manufacturing firms that declared international trade and financial data figures. We observed an inverse effect of import level on the long-term debt ratio and the negative impact of export level on the profitability. Every one-unit increase in import ratio decreases long term debt ratio by 0.0764, and every one-unit increase in export ratio decreases profitability by 0.0517. According to empirical findings there is no effect of import level on the short-term debt ratio, shareholder equity ratio and profitability. At the same time there is no effect of export level on the long term debt ratio, short term debt ratio and shareholder equity ratio.