Abstract: Examines the experiences of the patient, their family and healthcare professionals during the trajectory of a prolonged critical illness in an Intensive Care Unit (ICU). Conducts a qualitative, instrumental, multi-case study informed by the Chronic Illness Trajectory Framework. Analyses data from six linked cases (patient, family and clinicians) in four ICUs over a two-year period. Argues that identifying the sub-phases of a prolonged critical illness trajectory allows targeted interventions for each sub-phase.