Background Progressive ataxias are neurological disorders affecting balance, co‐ordination of movement and speech. Objective A qualitative study was undertaken to discover patients' experiences of ataxia and its symptoms. Participants Thirty‐eight people with ataxia recruited from patient support groups and two hospital outpatients departments. Design Cross‐sectional qualitative study with thematic analysis. Results These accounts highlight the limits of medicine in the context of a rare, incurable and disabling disorder, and the embodied uncertainties brought by slowly progressive diseases that lie at the boundaries of mainstream medical knowledge. The existential crises faced by people with ataxia are seemingly magnified by sometimes idiopathic aetiologies and the limited number of inherited conditions identifiable by the available genetic tests. Interviewees were drawn into a medical system that was focused mainly on the diagnosis process, with widely varying results. However, when asked, most had rather valued the provision of disability aids and physical therapies. Only one informant reported overcoming the myriad uncertainties of progressive ataxia, and their account supported the notion of ‘biographical repair’ in chronic illness. Conclusions Clinical uncertainties in ataxia constrained people's attempts to deal with their condition. The construction of the proactive, informed, medical consumer who is assumed to be a partner in care is problematic in the context of a rare and difficult‐to‐diagnose disease for which there is usually no cure. Service providers should be mindful of the need to manage patient expectations in relation to diagnosis and cure. More focus might usefully be placed on the provision of physical therapies and disability aids.