The purpose of this study is twofold: to determine the instructional variables of the inclusive classrooms in Turkey and to investigate to what extent the student behaviors change according to eco-behavioral characteristics of inclusive classrooms. The study group consisted of 44 students between the ages of six and 12 with mild disabilities who were placed in regular classrooms and their teachers. The Turkish version of the Code for Instructional Structure and Student Academic Response-Mainstream Version (MS-CISSAR) was used for data collection which was based on a momentary time sampling. The results of molar analysis indicated that the student behaviors displayed the most were no academic response, no task management, and no competing response. Attention and academic talk were found to be the teacher behaviors displayed the most during instruction. In addition, some student behaviors such as no academic response, no task management, writing, and self-stimulation were not affected by instructional grouping while the attention behaviors of the students were found to be affected by no instruction, no task, no activity, and paper-pen activity conditions. On the other hand, the writing behaviors of the students increased in math and decreased in the discussion condition. All the findings were discussed based on the Turkish mainstreaming system along with the difficulties of the mainstreaming implementation.