Research experiences are prominent in universities' undergraduate programmes across Australasia and are known to produce a variety of positive outcomes for students, educators, and universities. While there is growing research focused independently on undergraduate research and the role of assessment in higher education, how undergraduate research is assessed is not well understood. This paper reports on a scoping study and illuminates current assessment strategies and best practices in undergraduate research at universities in Australia and New Zealand across 17 disciplines. It offers empirical evidence and reflections based on a mixed-methods study involving 54 survey responses and 4 interviews with academics who engage in best practice. We explore what gets assessed and how, the main purpose of assessment, what drives undergraduate research assessment, and what criteria are used. Contributions and implications for undergraduate research assessment practice are discussed and key principles for design proposed.