This study aimed to evaluate the mathematics course curriculum that began to be implemented in 2018 in the 5th to 8th grade. The Eisner Educational Criticism Model was used in this study and the results were examined by taking the evaluation steps of the model. This is a qualitative study patterned with one case pattern is utilised. The data of the study were collected from 6 different secondary schools determined by the criterion sampling method. In this context, 13 secondary school mathematics teachers, 4 school principals, and 248 secondary school students participated in the research. As a data collection tool, the researchers used structured questions after receiving expert opinions related to these questions. Individual interviews were conducted with teachers and school principals, and focus group interviews were conducted with the students. As a result of the study, it was found that the mathematics teachers characterized changes to the 2018 mathematics course curriculum as a decrease in or displacement of the number of outcomes. The common points of view of the teachers, principals, and students about the 2018 math curriculum were collected via questions based on understanding and interpretation, called new-generation questions. Although the teachers stated that the new-generation questions were one of the positive aspects of the program, both the teachers and students expressed that they had difficulty with such questions. In addition, it was found that the school principals' knowledge of the 2018 mathematics course curriculum was insufficient. It was found that the students were aware that the subjects that they learned in math class would be useful in their daily, school, and future life. However, the students stated that the subjects should be made easier. Also, they stated difficulty with subjects in the field of numbers and operations learning.