After a stay in the intensive care unit, patients risk experiencing delusional memories, memory loss, and symptoms of posttraumatic stress. Since the 1990s, diaries have been kept for intensive care unit patients to help fill in memory gaps, aid psychosocial recovery, and improve health-related quality of life. More insight is needed into the application of diaries. The aim of our study was to explore how patients and relatives use diaries in the context of the illness trajectory.