The purpose of this study is to determine the effect of the mother tongue of the Syrian students on the process of learning Turkish as a foreign language. For this purpose, the subjects of investigation cover the impacts of using mother tongue during the courses and for extracurricular purposes, the changes in the usage of the mother tongue, the practices of the course lecturers, and the reflection of the elements of the mother tongue on the Turkish language skills, etc. during the learning process of Turkish. Case study of qualitative research designs was used in the study. A holistic evaluation is made with the student and lecturer views on the effect of the mother tongues on the Turkish learning processes of Syrian students and the researcher diaries kept in the classes; thus the qualitative research of case study is applied in here. The study was conducted with 23 students at A2 level learning the Kilis 7 Aralik University, Language and 5 lecturers teaching Turkish at this center. The data of the research was collected with student interview form, instructor interview form, and researcher’s journal. The collected data was analyzed using content analysis method. The findings related to the research questions was supported with examples from the data. Two different raters was used in data analysis. In the conclusion of the study, it has been determined that the mother tongue is used by the students to situations needed and the lecturers are flexible in this when necessary. The results of this study will help clarify the position of students using their native language in their Turkish learning process and organize the teaching environment accordingly. It is understood that, rather than banning or preventing the usage of the mother tongue, it should be utilized as a teaching tool when necessary. It can be said in teaching of Turkish that positive effects of the mother tongue should be used instead of having rigid rules on it The mother tongue that people initially learn from their mother and their immediate vicinity influences the foreign language they learn. The mother tongue in which the mental universe is shaped, determines the process and speed of the conceptualization of the foreign language. During the interaction between the mother tongue and the target language, the closeness or distantness between languages influences the ease and difficulty of the learning process. People tend to learn things more easily which has equivalence in its own language. This leads to language transfers. While positive transfers provide easiness, the negative transfers cause errors. The mother tongue makes, more or less, an impact on the learning process. What is important here is to turn it into an advantage and facilitate the learning process. It is necessary to take advantage of the mother tongue as an educational material instead of suppressing it by banning and preventing during the teaching of the foreign language.The purpose of this study is to determine the effect of the mother tongue of the Syrian students on the process of learning Turkish as a foreign language. For this purpose, the subjects of investigation cover the impacts of using mother tongue during the courses and for extracurricular purposes, the changes in the usage of the mother tongue, the practices of the course lecturers, and the reflection of the elements of the mother tongue on the Turkish language skills, etc. during the learning process of Turkish. Case study of qualitative research designs was used in the study. A holistic evaluation is made with the student and lecturer views on the effect of the mother tongues on the Turkish learning processes of Syrian students and the researcher’s journal kept in the classes; thus the qualitative research of case study is applied in here. The study was conducted with 23 students at A2 level learning Turkish at Language Teaching Practice and Research Center of the Kilis 7 Aralik University, and 5 lecturers teaching Turkish at this center. The easily available case sample, a purposive sampling method, was used in the study. In the study, an interview form was prepared for the students and the lecturers in order to get their opinions about the influence of Syrian students’ mother tongue on the Turkish learning process. Since the researcher joined to the courses of the students, the journals were kept during the learning process of the students. In this research, using qualitative analysis techniques, the views of the Syrian students and the lecturers as well as the researcher’s journal kept in the classes are examined with content analysis. In this study, which aims to determine the influence of the mother tongue in the process of Turkish learning of the Syrian students, it can be said that their mother tongue shapes their lives both in and out of the classroom. When we look at the usage of Arabic and Turkic, it is observed that mostly Arabic is used in the family and friend environments, and they have to use Turkish in places where interaction with Turks, such as school and work, is required. When the views of the lecturers are considered, it is stated that students usually prefer to speak Arabic with their friends and speak Turkish with Turkish students and lecturers. It has been reported that the students' mother tongues lead to negative transfers to Turkish regarding grammar and pronunciations. From the viewpoint of the lecturers, it is stated that the grammar and the pronunciation are transferred from their mother tongue, which leads to the mistakes. These transfers made by the students are also expressed by Bölükbaş (2011), Türkoğlu (2004), Odlin (1989). These negative transfers made by students are gradually diminishing in the process. The role of feedbacks and corrections given to students in this process is important. By using these effectively, the adaptation of the students to Turkish can be accelerated. Regarding the language of the lectures, most of the students stated that