Objective: Coronavirus 2019 disease presents in a spectrum that can range from mild viral infection to pneumonia. Common symptoms of coronavirus disease 2019 pneumonia include cough, sputum, and shortness of breath. High-frequency chest wall oscillation is a pulmonary rehabilitation method used for the recovery of pulmonary functions and removal of secretions in the lungs. The aim of the study was to evaluate the efficacy of high-frequency chest wall oscillation on patients with coronavirus disease 2019 pneumonia. Materials and Methods: In this study, 100 patients, between 18 and 70 years old, with a positive polymerase chain reaction result for coronavirus disease 2019, were included. Standard medical treatment was applied to all patients. In group rehabilitation, high-frequency chest wall oscillation treatment was applied twice a day for 20 minutes for 5 days. No additional intervention was made to the control group. Pulmonary function tests and oxygenation were evaluated on the first and fifth days. Patients’ high-flow oxygen, non-invasive mechanical ventilation, and invasive mechanical ventilation needs were evaluated and recorded. Results: Compared with the control group, the forced expiratory volume in 1 second, forced vital capacity, and peak expiratory flow rates were statistically higher in the rehabilitation group on the fifth day (P < .05). On evaluating the oxygenation of patients, the fifth day to first-day oxygen saturation difference was significantly higher in rehabilitation group than in control group (P < .05). Furthermore, the number of patients who needed non-invasive mechanical ventilation was lower in the rehabilitation group (P < .05). Conclusion: This study demonstrated that pulmonary rehabilitation applied with the high-frequency chest wall oscillation device in patients with coronavirus disease 2019 in the early period contributed to the improvement of oxygenation by providing significant improvement as observed in the pulmonary function tests of the patients.