The complexity of end-of-life communications has previously been described and found to be given late in the patient’s palliative care. There is a need for earlier and more continuous end-of-life-communications throughout the patient’s care to reduce anxiety, confusion, and promote participation. Registered nurses (RNs) have a unique closeness to the patient and the ability to identify early the need for end-of-life communication. The aim of this study was to describe crucial aspects of nursing in end-of-life communication in an oncology context. The study was designed as a qualitative content analysis of in-depth interviews with RNs working in oncology in-patient care units. Two domains were identified: before, and after end-of-life communications, with the categories importance of being well prepared to identify both the patient’s and their family’s needs. Cooperation and interaction between physicians and RNs were crucial to be able to support patients and their relatives around the clock. The presence of RNs encouraged further conversations about the patients’ conditions to gain insight into the new situation. End-of-life communication should not only be medicine oriented and performed by physicians. Involvement of RNs’ expertise enables increased patient/relative participation as well as reduced anxiety and suffering, creating clarity and safety for all involved in care.