The aim of this study was to identify and describe different ways surgical nurses understand their roles and interactions with patients and their families in a surgical care setting. The surgical nurse has an important role in supporting and encouraging the patient during the hospital stay. It can be a challenge for the nurse to quickly establish a trustful relationship with the patient. The assumption is that nurses' interactions with patients are affected by their understanding and expectations of the roles in the nurse-patient relationship. A qualitative interview approach was used and the interviews were analysed using the phenomenographic method. A strategic sample of 17 registered nurses in two hospitals in Sweden was interviewed. In the analysis four ways of understanding the nurse's role in interactions with the patient were identified: (A) Focusing on medical treatment, following prescribed instructions, and maintaining routines; (B) Providing information, giving service, and coordinating care and treatment; (C) Seeing patients as vulnerable people and helping and supporting them as individuals; and (D) Inviting patients to participate in the caring process and encouraging them to take responsibility in their own care. Seeing each patient as a person with individual needs and personal resources. The first way of understanding, A, focuses on the work task; the other three understandings focus on the patients, but differ in how the nurses see them as people. Understanding A represents a restricted and task-oriented approach, whereas the others are more patient-focused, but also more complex. To realise patient-centred care, nurses should pay attention to all aspects of the interaction. Nurses need to have time at ward meetings or in supervision to discuss and become aware of different ways of understanding their interactions and relationships with patients. In this way new areas of professional development may be opened up.