Background: Being a relative of a patient with oesophageal cancer can evoke strong emotions and uncertainty about the future. As a consequence of the treatment course for oesophageal cancer and an increase in outpatient treatment, relatives are becoming increasingly responsible for patients' physical and emotional care. There is a lack of research exploring relatives' experiences with illness, treatment and decision‐making. Aims and objectives: To explore relatives' experiences with illness, treatment of the patient and decision‐making in the context of oesophageal cancer. Design: A qualitative explorative design was chosen. Methods: We conducted two focus group interviews with 11 relatives. The analysis was based on Ricoeur's theory of interpretation. Results: Throughout illness and treatment, relatives faced the fear of loss, leading to distress and anxiety. Relatives were simultaneously taking responsibility and asserting a new role during treatment as they regarded treatment as a joint affair. Regarding decision‐making, relatives positioned themselves on the sidelines, awaiting the authority of the patients and healthcare professionals to give them space for participation. Conclusion: Relatives of patients with oesophageal cancer undergoing treatment are suppressing their anxiety and doubt about the future. As they are undertaking responsibility during treatment, they are claiming control in new areas, which leads to changing roles within the family. However, they do not feel empowered in decision‐making because they recognise patients' decision‐making authority. This study highlights the complexity of balancing patients' authority with acknowledgement of relatives' role as active collaborators.