This paper presents a study of teachers' professional judgement in the area of summative assessment. It adopts a situated perspective on assessment practices in classroom and school settings. The study is based on interviews with 10 sixth-grade teachers and on the assessment documents they used when determining end-of-term grades in students' report cards. The main findings from qualitative data analysis highlight both the individual cognitive and the socially situated aspects of teachers' judgements. The findings are discussed with respect to three levels of teacher judgement and the implications for activities of social moderation. (Contains 1 note.)