High-dose and long-term use of inhaled corticosteroids may cause systemic and local side effects such as opportunistic infections. Here we report a patient with asthma who developed a giant cavity in the lung while using inhaled salmeterol plus fluticasone propionate. A 57-year-old female patient presented with a three-week history of cough, hemoptysis, and dyspnea. She had a diagnosis of asthma for 4 years and was using an inhaled salmeterol plus fluticasone treatment intermittently for 2 years. A giant cavity was detected in the patient's chest X-ray. As a result of further investigations, three different microorganisms were isolated from the samples of sputum, bronchial lavage and lung biopsy. was the first microorganism that was isolated from the sputum and the bronchial lavage. Afterwards, was detected in both the bronchial lavage fluid and the histologic examination of the tissue samples obtained by percutaneous lung biopsy. Appropriate antibiotics and antifungals were prescribed. Moderate clinical and radiological response to the treatment was obtained. During the outpatient follow-up, growth which was sensitive to all of the major anti-tuberculosis drugs was reported in the mycobacterial culture, and the patient was started on anti-tuberculosis treatment. Tuberculosis and other opportunistic infections are a potential consequences of inhaled corticosteroids. Clinicians overseeing such patients need to be vigilant about the need for timely investigations about tuberculosis before and during prescribing medications containing inhaled corticosteroids.