This thesis focuses on the challenges in teaching students with undiagnosed mathematical difficulties in an inclusive environment. Previous research mainly focuses on medically diagnosed mathematical difficulties in special education. Therefore, this study will focus on undiagnosed mathematical difficulties that fall within the teacher’s responsibility in the main classroom, such as math anxiety, lack of motivation and low self-esteem. To include students with these difficulties in the teaching environment, the teacher needs to manage the entailed challenges. This study is based on a hypothesis and associated research questions to investigate what students see as difficulties within mathematics and, more indepth, what teachers see as challenges. The two surveys conducted are based on a quantitative survey and a semi-structured interview. Further, this thesis discusses the students’ difficulties within mathematics, the complexity of the inclusive process and the pedagogical competence. The results show that the time aspect and the need for an excellent pedagogical relationship with the students are two of the most common challenges for the teacher. Further, the conclusion confirms that to succeed with inclusive teaching, the teacher must practice relational pedagogy. Individualized education will also play an important role, which will be a significant challenge in larger groups of students. The study has been conducted under a short time limit, and therefore some convenience-selections have been necessary. Further research could advantageously contain the same hypothesis and be carried out in a larger population and for a more extended period.