The article explores the challenges of assessment in open distance learning (ODL). The authors argue that ultimately assessment should be about improving the quality of teaching and effective learning. It should be based on making expectations explicit and public, setting appropriate criteria and high standards for learning quality, systematically gathering, analyzing and interpreting evidence to determine how well performance matches expectations and standards, and using the resultant information to document, explain, and improve performance. However, getting all these variables to work in ODL presents mammoth challenges. How can ODL lecturers validate and authenticate students' written work? How can they tell whether the students' submitted work sufficiently reflects their knowledge and understanding? South Africa has inherited an unequal, racially skewed and inequitable educational provision from its apartheid past. This poses serious challenge for assessing quality. The article therefore seeks to understand these context-specific challenges of ODL assessment at UNISA.