We present the case of an 80-year-old woman with Mendelson's syndrome complicated by bacterial aspiration pneumonia caused by consciousness loss followed by vomiting resulting from putamen bleeding. Her condition worsened rapidly to develop respiratory failure, within a few hours; thereafter, she was intubated. Streptococcus agalactiae and Klebsiella oxytoca were detected from the aspirated sputum sample culture. She was diagnosed with acute respiratory distress syndrome with Mendelson's syndrome complicated by bacterial aspiration pneumonia. Corticosteroid and antibiotic administration improved her condition and led to successful extubation; therefore, these treatment modalities were invaluable. We suggest the clinical considerations for the corticosteroid and antibiotic use in such cases.