Sociological and anthropological analyses of hope in health-care contexts have tended to address institutional processes, especially the power dynamics that function through such systems or political economies of hope, which in turn shape interactions through which hopes are managed. This article extends this approach through a more detailed consideration of the experience of hoping itself. Our post-formal analysis denotes the tensions that are intrinsic and defining features of lifeworlds around hope, emphasising the dissonance and fragility of hoping. Drawing upon interview and observational data involving patients with advanced-cancer diagnoses who were taking part in clinical trials, we explore three main tensions which emerged within the analysis: tensions involving time and liminality between future and present; ontological tensions involving the concrete and the possible, the 'realistic' and the positive; and tensions in taken-for-grantedness between the reflective and the mundane, the specific and the ambiguous. Rather than three separate sets of tensions, those involving time, ontology and taken-for-grantedness are very much interwoven. In denoting the influence of social processes in engendering tensions, we bridge sociological and anthropological approaches with a more definition-oriented literature, developing understandings of hoping and its key characteristics in relation to other processes of coping amidst vulnerability and uncertainty.