The aim of this study is to investigate the effects of product diversification on the degree of international diversification of emerging country multinational companies (MNEs) by taking into account the moderating effects of corporate governance mechanisms. The sample consists of a total 325 publicly listed Turkish firms Istanbul Stock Exchange. These firms were chosen through a judgmental sampling procedure with respect to the various selection criteria using secondary data set. According to the findings, the product diversification has positive effect on the degree of international diversification unlike the studies carried out in the context of developed countries. At the board structure level, the size of the board and independent board member has a direct effect on international diversification while the family member has a moderating effect on it. Ownership concentration does not have any direct effect on the internalization diversification. However, the proportion of the first largest shareholder has a moderating effect on it.