OBJECTIVE: To estimate the effectiveness of a 10-week combined exercise training and home-based walking programme on daily physical activity (PA) compared with standard medical care in patients with moderate chronic obstructive pulmonary disease (COPD). DESIGN: Randomised controlled trial. SETTING: Primary care physiotherapy. PARTICIPANTS: Consecutive patients with stable COPD at Gold Stage II with a score of two or more on the Medical Research Council Dyspnoea Scale. INTERVENTION: Ten-week combined exercise training and home-based walking programme compared with standard medical care. MAIN OUTCOMES: At baseline and after 10 weeks, daily PA was evaluated by accelerometry using three levels of intensity and expressed as metabolic equivalent of task. In addition, daily activities (Physical Activity Scale for the Elderly), functional exercise capacity (6-minute Walk Test), health-related quality of life (Chronic Respiratory Questionnaire) and exercise self-efficacy (Exercise Self-Regulatory Efficacy Scale) were measured. RESULTS: Fifty-two patients {34 females; mean age 70.2 [standard deviation (SD) 9.5] years; mean forced expiratory volume in 1second 67% (SD 9.2) of predicted} were randomised. PA, adjusted for baseline differences, increased significantly in the intervention group compared with the control group, by 26.1minutes/day [95% confidence interval (CI) 7.3 to 44.9]. The increase in functional capacity between groups was clinically relevant (34.0m, 95% CI 2.3 to 65.6) in favour of the intervention group. CONCLUSIONS: A combined exercise training and home-based walking programme in primary care physiotherapy improved PA in patients with moderate COPD. Clinical trial registration number NL24766.018.08.