Physical activity (PA) is low in patients with Chronic Obstructive Pulmonary Disease (COPD). Identifying modifiable and non-modifiable correlates of PA give understanding of the individual behavior and provide future directions for PA enhancing interventions. As PA is complex and multidimensional, it should be embedded within a thorough framework. Therefore, the objective of this study is to identify correlates of PA in a comprehensive COPD population based on a broad ecological model, including physiological, psychological, socio-demographic and environmental dimensions.