Objective: This prospective observational study was designed to explore the relationships between post-traumatic stress disorder (PTSD), patients' memories of the intensive care unit (ICU) and sedation practices. Design: Prospective multi-centre follow-up study out to 3 months after ICU discharge. Setting: Two district general hospitals and three teaching hospitals across Europe. Patients and participants: Two hundred and thirty-eight recovering, post-ventilated ICU patients. Interventions: None. Measurements and results: Assessment of patients' memories of ICU was undertaken at 1-2 weeks post ICU discharge. Patients' psychological recovery was assessed by examining the level of PTSD-related symptoms and rate of PTSD by 3 months post ICU. The rate of defined PTSD was 9.2%, ranging from 3.2% to 14.8% in the different study ICUs. Independent of case mix and illness severity, the factors found to be related to the development of PTSD were recall of delusional memories, prolonged sedation, and physical restraint with no sedation. Conclusion: The development of PTSD following critical illness is associated with a number of different precipitating factors that are in part related to how patients are cared for within intensive care. This study raises the hypothesis that the impact of care within the ICU has an impact on subsequent psychological morbidity and therefore must be assessed in future studies looking at the way patients are sedated in the ICU and how physical restraint is used.