The aim of the reported study was to explore how science teachers made sense of their roles and responsibilities in teaching and assessing science coursework. The focus was on the teacher assessment, the feedback that teachers gave to students and, how they perceived their role when they taught and assessed students' science coursework reports. The research methodology included observation of science lessons, collection of marked students' reports and two interviews with each of the nine participant teachers. Two cases of teachers are considered as representative of the participant teachers and their perceptions and practices are compared and contrasted. Teachers either adopted the role of the examiner or combined the role of the teacher with that of examiner. They distinguished marking of science theory exercises from marking of coursework and, teaching theory from teaching investigations, on the basis that the grade they assigned to coursework contributed to the total grade for external exams. A key conclusion is that teaching and assessment of science coursework need to re-focus on learning. The study calls for changes in public policy for summative assessment to place more reliance on teachers' assessments and secondly, for changes in school practices in formative assessment for teachers to support students to learn in the case of science coursework.