BackgroundPhysical activity (PA) levels of people with coronary heart disease are low in the first 30 days after percutaneous coronary intervention (PCI), increasing the risk of recurrent cardiac events. Following PCI, PA counseling delivered by a physiotherapist before discharge may increase the PA levels of patients. Preliminary work is required to determine the effects of the counseling session compared to usual care.ObjectivesTo investigate the feasibility and potential efficacy of a brief physiotherapist‐led PA counseling session immediately after an elective PCI compared to usual care for improved PA early post‐PCI.MethodsUsing concealed allocation and blinded assessments, eligible participants (n = 30) were randomized to a physiotherapist‐led PA counseling session (30 min) or usual care (nurse‐led PA advice < 5 min). The primary outcome was daily minutes of moderate‐to‐vigorous PA (accelerometry; 3 weeks). Secondary outcomes included cardiac rehabilitation intention, anxiety and depression levels (Hospital Anxiety and Depression Scale), and quality‐of‐life (MacNew questionnaire). Recruitment, retention, and attrition were assessed for feasibility. Semistructured interviews were conducted with 13 participants to determine intervention acceptability, and barriers and enablers to PA.ResultsBetween and within‐group comparisons were not significant in intention‐to‐treat analyses. All feasibility criteria were met except for retention and attrition of participants. At 3 weeks, only 25% of participants were planning to attend cardiac rehabilitation, with no between‐group differences. Increased PA at 3 weeks was associated with participants that were younger, without other chronic disease,s and more active immediately following discharge. Interviews revealed personal, environmental, and program‐based themes for barriers and enablers to PA.ConclusionsA physiotherapist‐led PA counseling session may not improve PA levels early post‐elective PCI compared to very brief PA advice delivered by nurses. A larger multicentre randomized controlled trial is feasible with minor modifications to participant follow‐up. Further research is required.