AimsTo examine registered nurses' (RNs) behavioural, normative and control beliefs about end‐of‐life care for patients who are diagnosed with advanced and life‐limiting illnesses; and to identify the barriers and facilitators they experience when providing end‐of‐life care.DesignA sequential explanatory mixed methods study.MethodAn online cross‐sectional survey was conducted using the Care for Terminally Ill Patient tool among 1293 RNs working across five hospitals in the Kingdom of Saudi Arabia. Online individual semi‐structured interviews with a subgroup of survey respondents were then undertaken. Data were collected between October 2020 to February 2021.ResultsA total of 415 RNs completed the online survey, with 16 of them participating in individual interviews. Over half of the participants expressed the belief that end‐of‐life care is most efficiently delivered through multidisciplinary team collaboration. The majority of participants also believed that discussing end‐of‐life care with patients or families leads to feelings of hopelessness. Paradoxically, the study revealed that more than half of the participants held the negative belief that patients at the end of life should optimally receive a combination of both curative and palliative care services. The results showed that nurses' beliefs were significantly associated with their age, religion, ward type, level of education and frequency of providing end‐of‐life care. Data from the qualitative interviews identified four themes that explored RNs' beliefs and its related factors. The four themes were ‘holistic care’, ‘diversity of beliefs’, ‘dynamics of truth‐telling’ and ‘experiences of providing end‐of‐life care.’Implications for the Profession and/or Patient CareWherever possible, patients at the end‐of‐life should be cared for in specialist settings by multidisciplinary teams to ensure effective, high‐quality care. Where this is not possible, organisations should ensure that teams of multidisciplinary staff, including nurses, receive education and resources to support end‐of‐life care in non‐specialist settings. Hospitals that employ foreign‐trained nurses should consider providing targeted education to enhance their cultural competence and reduce the impact of different beliefs on end‐of‐life care.