The purpose of this study is to investigate writing self-efficacy of international students majoring at Inonu University. Ninety-three participants were from seventeen countries and at the time of the study they had completed a one year Turkish language course before proceeding with their majors. In order to measure the writing self-efficacy of the participants, a scale developed by Buyukikiz (2012) was employed. The findings of the study suggest that the participants have little difficulties in expressing their ideas in the written form. The fact that they scored less in lower level skills suggests that they have more difficulties with the grammar and spelling of Turkish. This study illustrates that since Turkish is an agglutinating language, more attention should be paid to the spelling and grammar rules in Turkish writing courses.