This study aimed to evaluate all aspects of the 2018 Mathematics curriculum for 5th grade students in secondary school. In the study, concurrent nested design, one of the mixed research methods, was used. The participants for this study consisted of 204 5th grade students and 10 mathematics teachers in their 2017/2018 academic year. Quantitative data were collected with a 56-item student self-efficacy perception questionnaire and for qualitative data a semi-structured teacher interview form was developed by the researcher. The results obtained were compared with the 2005 and 2013 Mathematics curriculum. In analysing the 2005 and 2013 curriculum document analysis technique was used. For the 2018 Mathematics curriculum, some statistics such as percentage, frequency and arithmetic mean were used in the analysis of quantitative data. In the analysis of qualitative data, content analysis technique was used. It was emphasized in the study that the objectives of 2018 mathematics curriculum were appropriate to the student level and that the students were sufficient in terms of objectives. Moreover, the reduction in the number of objectives is regarded as a positive development by the teachers. Meanwhile, most of the students stated that geometric objects are the most difficult subject in the sub-learning field. This result is similar to the results obtained from interviews with teachers. Problems with equipment deficiency, crowded classes, and measurement evaluation process were observed to still continue.