Sarcoidosis is a multisystem granulomatous disease of unknown etiology and is pathologically characterized by non-caseating granulomas in the organs involved. We herein report a case of sarcoidosis in a Japanese woman with acute respiratory failure, diagnosed using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) on the ventilator after intubation. Only a few cases of previously undiagnosed sarcoidosis presenting acute respiratory failure have been reported. It is important to be aware that undiagnosed sarcoidosis may present with acute respiratory failure. Therefore, EBUS-TBNA under mechanical ventilation may be useful for the immediate diagnosis of patients.