Recent work on biographical disruption has emphasised the critical importance of timing and context to the understanding of the effects of illness on identity. This paper takes a different approach by examining the inter-relationship between illness and key sources of identity, in this instance HIV infection and motherhood. It is argued that, viewed in this light, biographical disruption remains a powerful analytic framework with which to explore the intense threat which may be posed to key identities by chronic, potentially fatal illnesses, and the fundamental re-working of such identities occasioned by such threats. With reference to the empirical study on which this paper draws, it is shown that the twelve respondents' emphasis on their need to survive and to protect their children, represented a fundamental re-formulation of their identities as mothers and, therefore, a type of biographical disruption while paradoxically also containing elements of biographical reinforcement. It is further argued that the incorporation of such key identities into the analysis problematizes work that suggests that biographical disruption is less relevant to those who have experienced difficult lives, while also highlighting the need to take greater account of gender and caring responsibilities in further work in this field.