The students might have either negative or positive feelings for different components of foreign language process. While positive feelings and emotions support the language acquisition process and push the students to learn the language, negative feelings block the process as they cause the learner to erect barriers to learning a foreign language. In case this process is directed by a teacher who is aware of the barriers of the students and sensitive to them, it is possible to replace negative feelings with the positive ones. The purpose of the current study is to reveal the sources of the negative feelings which hinder EFL learning process of the students in English language preparatory program in Eskisehir Osmangazi University Foreign Languages Department. Case study research design was used in order to examine the phenomenon of underlying reasons of negative feelings students associate with language learning process. Self-reports of the participants constituted the data source of the study. The data of the study was gathered through the interviews conducted with 31 students and 20 English instructors and the data gathered was analyzed inductively. The findings revealed four categories that represent the sources of students' negative feelings: teacher-oriented negative feelings, classroom oriented negative feelings, and system oriented negative feelings, and student-oriented negative feelings. The results imply a need for instructional design studies targeting to incorporate affective domain variables into teacher education programs and in-service teacher training programs. Also, suggestions for future research are presented.