Assessment literacies for both teachers and students matter because assessment is central to learning and influences behaviours and practices of both. Student assessment literacies have largely been ignored, which is surprising given discourses supporting students taking responsibility for their own learning. Here we investigate the understandings of assessment literacies, especially summative assessment (SA) and formative assessment (FA), of a group of 83 year-three health sciences undergraduates. We found limited and ineffective dialogue between students and teachers about assessment. Even after more than two years at university, students show a lack of common understanding, or no understanding, of the terms SA and FA despite them having become common parlance in academic discourses. From their responses we concluded that 29% of students understood SA, 29% understood FA, and 18% understood both. This lack of understanding is worrying since it counters somewhat the notion that students are central to their own learning. The lack is mirrored by teachers, and to some extent by the literature in general. We contend that a lack of common understanding and theoretical framework has potential to hinder the engagement and progress of students and we call for remedy, starting from a student perspective.