Objective: To evaluate a partnership model of care for patients with a diagnosis of chronic obstructive pulmonary disease (COPD). Design, setting and participants: Cluster randomised controlled trial with blinded outcome assessment of 44 general practices in south-western Sydney comprising 451 people with a diagnosis of COPD, conducted between 2006 and 2009. Intervention: Participants from intervention group practices were visited at their home by a registered nurse with specific training in COPD care who worked with the general practitioner, the patient and other health professionals to develop and implement an individualised care plan based on best-practice guidelines. Participants from control group practices received usual care. Main outcome measures: The primary outcome was disease-related quality of life measured using the St George's Respiratory Questionnaire (SGRQ) at 12-month follow-up. Other outcomes were overall quality of life, lung function, smoking status, immunisation status, patient knowledge of COPD, and health service use. Results: Of the 451 participants, 257 (57.8%) were confirmed as having COPD on post-bronchodilator spirometry. Follow-up was completed for 330 patients (73.2%). At 12 months, there was no statistically significant difference in the mean SGRQ scores between intervention and control groups (38.7 v 37.6; difference, 1.1; 95% CI, - 1.53-3.74; P =0.41) or in measures of quality of life, lung function and smoking status. Compared with the control group, in the intervention group, attendance at pulmonary rehabilitation was more frequent (31.1% v 9.6%; OR, 5.16; 95% CI, 2.40-11.10; P =0.002) and the mean COPD knowledge score was higher (10.5 v 9.8; difference, 0.70; CI, 0.10-1.21; P=0.02). Conclusion: The nurse-GP partnership intervention did not have an impact on disease-related quality of life at 12-month follow-up. However, there was evidence of improved quality of care, in particular, in attendance at pulmonary rehabilitation and patient knowledge of COPD.