Student self-assessment occurs when learners make judgements about aspects of their own performance. This paper focuses on one aspect of quantitative self-assessments: the comparison of student-generated marks with those generated by teachers. Studies including such comparisons in the context of higher education courses are reviewed and the following questions are addressed: (i) do students tend to over- or under-rate themselves vis-á-vis teachers?, (ii) do students of different abilities have the same tendencies?, (iii) do students in different kinds or levels of course tend to under- or over-rate themselves?, (iv) do students improve their ability to rate themselves over time or with practice?, (v) are the same tendencies evident when self-marks are used for formal assessment purposes?, and (vi) are there gender differences in self-rating? The paper also discusses methodological issues in studies of this type and makes recommendations concerning the analysis and presentation of information.