RATIONALE: Increasing physical activity is a key therapeutic aim in COPD. Pulmonary rehabilitation (PR) improves exercise capacity, but there is conflicting evidence regarding its ability to improve physical activity levels. OBJECTIVE: To determine whether using pedometers as an adjunct to PR can enhance time spent in at least moderate intensity physical activity (time ≥ 3METs) in people with COPD. METHODS: In this single-blinded randomized controlled trial, participants were assigned 1:1 to receive control (PR comprising 8 weeks, two supervised sessions/week) or intervention (PR plus pedometer-directed step targets, reviewed weekly for 8 weeks). The randomisation process used minimisation to balance groups for age, sex, FEV1 % predicted, and baseline exercise capacity and physical activity levels. Outcome assessors and PR therapists were blinded to group allocation. The primary analysis was by intention-to-treat and the trial registered with clinicaltrials.gov (Ref. NCT01719822). MEASUREMENTS: The primary outcome was change from baseline to 8 weeks in accelerometer-measured daily time ≥3METs. MAIN RESULTS: 152 participants (72% male; mean (SD) FEV1 % predicted 50.5 (21.2); median (Q1, Q3) time ≥3METS 46 (21, 92) minutes) were enrolled to intervention (n=76) or control (n=76). There was no significant difference in change in time ≥3METs between the intervention and control groups at 8 weeks (median (Q1, Q3) difference 0.5 (-1.0, 31.0) minutes; p=0.87) or at the 6 month follow-up (7.0 (-9, 27) minutes; p=0.16). CONCLUSION: Pedometer-directed step count targets during an outpatient PR program did not enhance moderate intensity physical activity levels in people with COPD. Clinical trial registration available at www.clinicaltrials.gov, ID NCT01719822.