Pulmonary rehabilitation has emerged as a gold standard of care for symptomatic patients with chronic obstructive pulmonary disease (COPD) and is now prominently placed in clinical practice guidelines for the treatment of this disease [1]. In fact, pulmonary rehabilitation is one of the most effective interventions for alleviating dyspnea in the patient with chronic respiratory disease. Emerging evidence also supports its use in other chronic respiratory disorders, such as interstitial lung disease (ILD) [2]. This chapter discusses the definition and concept of pulmonary rehabilitation as an intervention that can reduce dyspnea, arguably the overriding symptom of individuals with chronic lung disease and the major factor impacting their quality of life.