Diagnostic procedures in pregnant wowen is limited and is usually delayed, especially so if she is on mechanical ventilation. A 28-year-old pregnant woman with severe dyspnea was referred to our hopital under the impression of miliary tuberculosis. The respiratory failure was so severe that patient had to be managed with mechanical ventilator under clinical imression of overwhelming pneumonia or pulmonary tuberculosis. But the patient's conditions deteriorated. Bronchoscopy and blind transbronchial lung biopsy performed to determine the nature of the etiology, and to our surprise, revealed squamous cell carcinoma of the lung.