Critical care hospitalisation is emotionally overwhelming for the relatives of patients. Research has shown that religiosity is an effective coping resource for people with health related problems and has been correlated with better health outcomes. However the processes by which religiosity is utilized and its effects on relatives of critically ill patients have not been adequately explored. This article presents relatives' experiences and processes of religiosity; it is part of a wider grounded theory study on the experiences of critically ill patients' relatives in Greece. Twenty-five relatives of patients in the intensive care units of three public general district hospitals in Athens, Greece, participated in 19 interviews. Religiosity was found to be the main source of hope, strength and courage for relatives and was expressed with church/monastery attendance, belief in God, praying, and performing religious rituals. Health care professionals should pay attention and understand these aspects of coping.