The objective of this study was to provide lung disinfection by nebulizing ozone gas with distilled water and olive oil for patients who have clinical symptoms due to coronavirus disease 2019 (COVID-19). The study attempted to reduce the viral load of COVID-19 in the lungs of patients, to provide a faster response to medical treatment. Between August 2020 and September 2020, 30 patients who met the study criteria were prospectively evaluated. There were 2 groups with 15 patients in each group: patients in control group were not treated with ozone and only received standard COVID-19 treatment; patients in ozone group received lung disinfection technique with ozone and standard COVID-19 treatment. A statistically significant difference was found in the length of stay in hospital, change in C-reactive protein, polymerase chain reaction results after 5 days, and computed tomography scores between two groups. There was no statistically significant difference in D-dimer, urea, lactate dehydrogenase, lymphocyte, leukocyte, and platelet between two groups. According to the data, we think that the lung disinfection technique applied with ozone inhalation reduces the rate of pneumonia in COVID-19 patients and makes the patients respond faster to the treatment and become negative according to the polymerase chain reaction tests. The study was approved by the Ethical Committee of the İstanbul Medipol University Clinical Trials (approval No. 0011) on July 2, 2020.