Objective: To determine whether supported self management in chronic obstructive pulmonary disease (COPD) can reduce hospital readmissions in the United Kingdom. Design: Randomised controlled trial. Setting: Community based intervention in the west of Scotland. Participants: Patients admitted to hospital with acute exacerbation of COPD. Intervention: Participants in the intervention group were trained to detect and treat exacerbations promptly, with ongoing support for 12 months. Main outcome measures: The primary outcome was hospital readmissions and deaths due to COPD assessed by record linkage of Scottish Morbidity Records; health related quality of life measures were secondary outcomes. Results: 464 patients were randomised, stratified by age, sex, per cent predicted forced expiratory volume in 1 second, recent pulmonary rehabilitation attendance, smoking status, deprivation category of area of residence, and previous COPD admissions. No difference was found in COPD admissions or death (111/232 (48%) v 108/232 (47%); hazard ratio 1.05, 95% confidence interval 0.80 to 1.38). Return of health related quality of life questionnaires was poor (n=265; 57%), so that no useful conclusions could be made from these data. Pre-planned subgroup analysis showed no differential benefit in the primary outcome relating to disease severity or demographic variables. In an exploratory analysis, 42% (75/150) of patients in the intervention group were classified as successful self managers at study exit, from review of appropriateness of use of self management therapy. Predictors of successful self management on stepwise regression were younger age (P=0.012) and living with others (P=0.010). COPD readmissions/deaths were reduced in successful self managers compared with unsuccessful self managers (20/75 (27%) v 51/105 (49%); hazard ratio 0.44, 0.25 to 0.76; P=0.003). Conclusion: Supported self management had no effect on time to first readmission or death with COPD. Exploratory subgroup analysis identified a minority of participants who learnt to self manage; this group had a significantly reduced risk of COPD readmission, were younger, and were more likely to be living with others. Trial registration: Clinical trials NCT 00706303.