This paper aims to investigate the methodological bases of the 1991 ELT curriculum for the secondary schools (1st, 2nd, and 3rd grades), the 1997 ELT curriculum for the 4th and 5th grades of the primary education, the 2006 ELT curriculum for the primary education (grades four to eight), 2013 and 2018 ELT curricula for the primary and secondary schools (grades two to eight) in Turkey by utilizing document analysis as a form of qualitative research. Investigation of the other components of ELT curricula, namely, needs, goals and objectives, syllabus, assessment, and evaluation is not the main concern of the study but some of these components will also be mentioned to shed light on the adopted methodology in the mentioned curricula. It is argued that all the curricula investigated present the teachers with an eclectic approach while some of these curricula (e.g. 1991, 2013, 2018 curricula) state it explicitly and some of them (e.g. 1997 and 2006 curricula) indicate it implicitly by suggesting the teachers get benefit from different principles and/or activities from different methods and/or approaches. It is also observed that the principles and/or activities of the communicative approach are present in all these curricula although their dominance varies from one curriculum to the other. In line with this observation, the study indicates that the commonly articulated thesis in the literature that the communicative approach was integrated, for the first time, into the Turkish ELT curricula with the 1997 curriculum is not valid. It is also argued that besides adopting an eclectic approach with more focus on the communicative approach, the 2013 and 2018 ELT curricula, unlike all the previous curricula, claim to adopt the action-oriented approach but in reality, these two curricula are not action-oriented. The reason behind this problem is purported to be the misinterpretation of the action-oriented approach by the developers of the curricula as well as some other ELT researchers in Turkey.