This study aimed to validate the Comprehensive International Classification of Functioning, Disability and Health (ICF) Core Set for obstructive pulmonary diseases (OPDs) from the perspective of patients with chronic obstructive pulmonary disease. A cross-sectional qualitative study was carried out with outpatients with chronic obstructive pulmonary disease using focus groups with an ICF-based approach. Qualitative data were analysed using the meaning condensation procedure by two researchers with expertise in the ICF. Thirty-two participants (37.5% women; 63.8±11.3 years old) were included in six focus groups. A total of 61 (86%) ICF categories of the Comprehensive ICF Core Set for OPD were confirmed. Thirty-nine additional second-level categories not included in the Core Set were identified: 15 from the body functions component, four from the body structures, nine from the activities and participation and 11 from the environmental factors. The majority of the categories included in the Comprehensive ICF Core Set for OPD were confirmed from the patients’ perspective. However, additional categories, not included in the Core Set, were also reported. The categories included in the Core Set were not confirmed and the additional categories need to be investigated further to develop an instrument tailored to patients’ needs. This will promote patient-centred assessments and rehabilitation interventions.