An increased proportion of deaths occur in the intensive care unit (ICU).We performed this prospective study in 41 ICUs to determine the prevalence and determinants of complicated grief after death of a loved one in the ICU. Relatives of 475 adult patients were followed up. Complicated grief was assessed at 6 and 12 months using the Inventory of Complicated Grief (cut-off score >25). Relatives also completed the Hospital Anxiety and Depression Scale at 3 months, and the Revised Impact of Event Scale for post-traumatic stress disorder symptoms at 3, 6 and 12 months. We used a mixed multivariate logistic regression model to identify determinants of complicated grief after 6 months.Among the 475 patients, 282 (59.4%) had a relative evaluated at 6 months. Complicated grief symptoms were identified in 147 (52%) relatives. Independent determinants of complicated grief symptoms were either not amenable to changes (relative of female sex, relative living alone and intensivist board certification before 2009) or potential targets for improvements (refusal of treatment by the patient, patient died while intubated, relatives present at the time of death, relatives did not say goodbye to the patient, and poor communication between physicians and relatives).End-of-life practices, communication and loneliness in bereaved relatives may be amenable to improvements. @ERSpublications End-of-life care and communication in the ICU are associated with the prevalence of complicated grief http://ow.ly/DCqjB