Today, the rapid development of technology causes a great change and transformation process in the field of education. In this process, the importance of technological pedagogical content knowledge (TPACK) increases for teachers to use technology effectively. In this process, it is thought that mathematics teachers should improve their TPACK especially in the use of assessment tools in EBA. In addition, mathematics teachers should have sufficient knowledge about the use of teaching methods, materials and technological tools in order for students to be successful in mathematics. At this point, it is thought that teachers' TPACK is critical for optimizing students' learning process and providing an effective mathematics education. In this context, the aim of the study is to examine the TPACK of mathematics teachers in the context of demographic and frequency of use of EBA assessment tools and to make some suggestions as a result. The study was designed with the survey model of quantitative method. Mathematics teachers working in public and private schools in Eskişehir province constitute the population of the study. Within the scope of the study, the link of the relevant data collection tool was sent to the study group by obtaining the necessary application permissions and data were collected from 369 mathematics teachers. As a result of the study, it is concluded that mathematics teachers need to develop their TPACK in order to improve students' mathematics skills and optimize students' learning process, and that teachers should have knowledge about the use of technological tools and online assessment tools such as EBA and be able to use these tools effectively. In addition, in the light of this study, it is recommended that mathematics teachers should research technological tools and materials that they can use in mathematics education and use EBA assessment and evaluation tools more frequently in order to improve their TPACK. Finally, it is suggested that in-service courses, trainings, etc. on the use of technology in education should be organized for teachers to ensure their personal development.