Abstract Objectives This paper provides a theoretical account of nurses’ collaboration with patients with chronic obstructive pulmonary disease during non-invasive ventilation treatment in hospital. Background Despite strong evidence for the effect of non-invasive ventilation treatment, success remains a huge challenge. Nurse–patient collaboration may be vital for treatment tolerance and success. A better understanding of how nurses and patients collaborate during non-invasive ventilation may therefore contribute to improvement in treatment success. Design A constant comparative classical grounded theory. Method The data comprised sessions of qualitative participant observation during the treatment of 21 patients with non-invasive ventilation that included informal conversations with the nurses and semi-structured interviews with 11 patients after treatment completion. Data were collected at three intensive care units and one general respiratory ward in Denmark. Results Succeeding emerged as the nurses’ main concern in the nurse–patient collaboration during non-invasive ventilation treatment. Four collaborative typologies emerged as processing their main concern: (1) twofold oriented collaboration; (2) well-being oriented collaboration; (3) outcome oriented collaboration; and (4) absent collaboration. Conclusions This study offers a theoretical account of nurses’ main concern and how they activate different ways of collaboration to achieve successful treatment. We offer a theoretical basis for developing complex interventions.