The aim of this study is to explore how five teachers in the subject of religion implement assessment in their classes. The study will take place in five different schools, where four teachers are working in upper secondary schools and one works at elementary school. The purpose is to find out how teachers apply to assessment practices in subject of religion and what challenges they see with them. The questions that have permeated the study are what challenges teachers in the subject of religion face when assessing students, and how they view formative and summative assessment. The method will include a qualitative method in the form of semi-structured interviews that will be based on an interview guide and questions around the issues. In order for analysis to be carried out based on the interviews, two theories will be used to discuss and analyze the material collected. These two theories are Kane's validity model and the frame factor theory. In the analysis, I use two themes that include the summative and formative assessment, which I will then discuss based on theories and previous research. The result of this study is that teachers regard time as a factor in not being able to give students full formative assessments. They also regard time as the biggest challenge in the teaching profession. However, it is the formative assessment that is applied by all teachers and the summative is applied only when a grade is to be established. The conclusion is that teachers in the subject of religion work within the framework they need to relate to. These frameworks are time periods and organizational procedures that include curriculum and knowledge requirements in the subject of religion. This is the challenge for all teachers who have been interviewed in this study. The summative is not optimal for the teachers as it prevents the student from learning therefore it is used at the end of a course.