Background: Chronic Obstructive Pulmonary Disease (COPD) is a common and treatable condition, often characterized by dyspnea with or without wheezing, cough, and excessive sputum production. This condition leads to ineffective breathing patterns, decreased functional capacity, and limitations in activities of daily living. Physiotherapy management is required to help clear the airways, reduce dyspnea, improve ventilation, and enhance respiratory function. Objectives: To determine physiotherapy management in cases of COPD aimed at reducing dyspnea, improving lung volume capacity through enhanced thoracic expansion, and increasing functional capacity in activities of daily living. Methods: A case study was conducted on a COPD patient who received four treatment sessions using modalities including nebulizer therapy, the Active Cycle of Breathing Technique (ACBT), and diaphragmatic breathing exercises. Evaluations were performed before and after the interventions using the Borg Scale to assess the degree of dyspnea, thoracic expansion anthropometry to evaluate chest expansion, and the Modified Medical Research Council (mMRC) Dyspnea Scale to assess activity tolerance. Results: After four physiotherapy sessions consisting of nebulizer therapy, ACBT, and diaphragmatic breathing exercises, the patient showed improvement, with the Borg Scale score decreasing from grade 5 to grade 2, thoracic expansion increasing from 1–1.5 cm to 2 cm, and activity tolerance score improving from grade 3 to grade 2. Conclusion : A 63-year-old male patient (Mr. S) diagnosed with COPD demonstrated reduced dyspnea, increased inspiratory capacity, and improved activity tolerance following physiotherapy interventions including nebulizer therapy, ACBT, and diaphragmatic breathing exercises. Keywords: Chronic Obstructive Pulmonary Disease, Nebulizer, ACBT, Diaphragmatic Breathing Exercise.