This study was carried out by using the nested single case study design, which is a qualitative case study method, in order to determine the experiences and thoughts of the instructors about the flipped classroom method. The experiences of the instructors related to the flipped classroom were examined within the framework of Technological Pedagogical and Content Knowledge (TPACK). The study group of the research consisted of instructors working at a state university in Turkey, and taking part in 4 different departments determined by purposive sampling. Five instructors were interviewed, and one instructor's lesson was observed. The data were collected through a semi-structured interview form and observation form developed by the researchers. Content analysis method was used in the data analysis. The definitions of the flipped classroom, the technologies used in the flipped classroom, the effects of the flipped classroom on students, the difficulties encountered in the flipped classroom, and the themes and sub-themes for making the flipped classroom more effective were determined as a result of the interviews with the instructors. There were various positive and negative opinions of the participants under each topic. According to the results of the study, TPACK-related competencies of the instructors in integrating technology into learning environments also had an important place in the development or provision of course materials as well as the use of these materials in the flipped classroom.