In mathematics, it is aimed to teach the learning outcomes in the curriculum in order to increase student learning to the desired level. It is possible to understand whether this aim has been achieved or not by the process of assessment and evaluation. Assessment and evaluation in mathematics education is as important as the teaching of the subject. During the process of assessment and evaluation, it is aimed that students can express what they have learned comfortably. The concept maps are stated as a method arousing students’ interest and providing them to express themselves comfortably not only during the process of teaching but also during the process of assessment and evaluation. In this context, the study aims to evaluate secondary school fifth-grade students’ learning of the concepts related to the subject of angles by means of the concept maps. In the study, the case study design was used since it was aimed to determine the learning status of 40 middle school 5th grade students about the angles concept. The research was carried out with 20 study groups by forming groups of two in the students' classes. After the data were collected, the concept maps were examined by the researchers and the codes were determined by the content analysis. According to the results obtained; it was observed that students have mistakes in the types of angles and their definitions; especially with regard to the concept of full and right angles. It has been reached that the students have generally made the definition and drawing of the angle types they determined correctly. In addition, it has been concluded that the concept map can be used easily in mathematics as an assessment and evaluation tool and it is a more efficient tool for students than the traditional methods. It is also concluded that students have correctly expressed the relations between concepts in the concept maps they created themselves. It is recommended that teachers should give more space to the concept maps in mathematics lessons.