Since the foundation of the Republic of Turkey, the Kurdish question has been the biggest ethnic issue of Turkey which became one of the important subjects in the agenda of Turkey and international organizations. The question has certain impacts on the stability of the country that is today being associated with security and terror issues. Consequently the Kurdish question challenges the state and the country in the aspects of ethnic problems, human rights, democracy, as well as socio-economic and political. The aim of this article is to uncover how the Kurdish question challenges the stability in terms of Turkish state and the Kurds. In this regard, the research engages several objectives; evaluations of approaches toward Kurdish issue, analyzing historical background, and evaluation of the issue in the present time. Research methods of the paper consists of comparative analysis of decision, document analysis on the reports and agreements, descriptive method on the developments, and media analysis to engage relevant news. The main results of the research are concluded on variety aspects of the Kurdish question, such as security, terrorism, minority issue, human rights, and so on. Thus, it creates certain impacts on the stability in Turkey both in terms of state and the Kurds regionally and internationally.