Spirituality can be a crucial resource to draw on to make sense of critical situations that mark a turning point in individual and collective biographies. In these cases, a ritual and symbolic response to the trauma may occur, bringing to the surface a «latent spirituality», that is, a tacit propensity towards the sacred that manifests itself in unexpected ways, even in those who do not normally believe or practice, in extraordinary situations that engender fear, anomie or disorientation and that have profound existential repercussions. This article aims to investigate the latent spirituality in the face of the critical event represented by the onset of severe disease, based on the analysis of spiritual illness narratives collected in Italy through qualitative interviews with oncological patients. The narratives show how the condition of suffering can bring to light an unexpressed spirituality, consisting of the revitalization of previous traditional faith or the elaboration of an innovative lay spirituality. Data confirm how pathology constitutes a biographical fracture, accompanied by questions and needs of a religious and spiritual nature. In contrast to the prevailing approach in the medical humanities where spirituality is interpreted as a starting resource to which sufferers resort to cope toward the disease, these results indicate that the spiritual dimension is an emerging aspect along the therapeutic pathway and that it is transformed by reflecting the temporality of the biographical experience of illness.