This article addresses two concerns that are central to much of the qualitative research currently ongoing in both the social sciences and other fields of social research: the status awarded to biographical knowledges and, associatively, how such knowledges are dealt with in concrete research. The first section calls attention to the unreliability of memory in order to cast doubt on the veracity of lay actors' accounts and thus question their position in social research. The second section, taking up this challenge, addresses a number of critical issues related to both the theoretical and the empirical status of biographical knowledges in qualitative research. Foremost of these are how both 'ignorance' and the dynamic nature of memory are integral to the construction and reconstruction of biographical knowledge. The methodological considerations that arise from this discussion are then considered more explicitly. The article seeks to provoke, rather than foreclose, critical thought and debate.