Assessment literacy is considered essential to modern teaching. Over time, assessment literacy has evolved to include both measurement and assessment for learning perspectives. At the same time, research into teachers' conceptions of the purpose and role of assessment demonstrates increasing evidence of the impact of teachers' conceptions on assessment practices. The conjunction of these two factors, assessment literacy and conceptions of assessment has not been adequately explored. This study addresses this need by examining the impact of a master's level teacher education course in educational assessment on student teachers' expressed literacy in and conceptions of assessment. Achievement data were collected and interviews conducted in a class of 32 pre-service and practicing teachers. Inferential analysis and qualitative coding were applied to the data. Analytical results included a strong, polarized affective component. These positive and negative affective conceptions appeared independent of level of academic achievement. Academic achievement appeared to play a role in allowing deeper articulation of conceptions, but did not accompany particular conceptual changes. These findings suggest that while fluency in factual knowledge (i.e. assessment literacy) was enhanced; conceptions of assessment that may influence application of assessment literacy were not changed through the mediating influence of the assessment course. Implications of the results and this apparent disconnection between assessment literacy, teacher education and practice are explored.