Background: People with amyotrophic lateral sclerosis become dependent on caregivers for daily activities and to perform self‐care activities at home. The family caregiver has an important role in the care. The patient decides and controls care but depends on the caregiver to implement self‐care behaviours. The quality of caregiver–patient relationships could influence clinical outcomes, as it occurs in other illnesses, so the aim of this study was to investigate the relationship between the Amyotrophic Lateral Sclerosis patients and their family caregiver and how it impacts care, and patient and caregiver outcomes. Methods: We interviewed 22 patients/caregivers in a Neuromuscular Clinical Center in the South of Europe, between July and October 2018. A Grounded Theory approach was used, comprising line by line 'initial coding', memos writing, 'focused coding', advanced memos and categories definition. Findings: From the interviews three main categories emerged: 'reciprocity', 'loving to care' and 'changing to care' and four secondary categories: 'having support', 'sharing suffering', 'protecting each other' and 'thinking positive'. A stable and calm relationship between patient and caregiver, characterised by reciprocity, mutual help and affection affected patient self‐care provided at home and the caregiver burden. The concept of mutuality seems to describe this relationship, despite the patient's dependence on the caregiver. The relationship with health professionals and educational interventions could influence the quality of the relationship. Conclusions: Further studies are needed to describe the quality of the relationship in this dyad, to investigate the presence of mutuality and how it affects patient and caregiver outcomes.