Patients are increasingly involved in health informatics research. Researchers are always aware of the ethical dimensions of their research, but studies in the field with patients--especially among the frail, elderly, cognitively impaired--present specific additional 'everyday moral dilemmas'. Reflecting on experiences of a hospital study of patients with dementia, this paper draws attention on the type and constant presence of this situated ethics, the immediacy of decision-making, and the importance of everyday ethics for health informatics.