Nitrofurantoin is an antimicrobial agent commonly used for urinary tract infections. This drug may cause pulmonary toxicities, the manifestations of which range from acute self-limiting reactions to chronic pathologies. Here, we report the case of a 72-year-old male who was admitted with progressive cough and dyspnea for 4 months. On physical examination, his respiratory rate was 26/min and oxygen saturation was 84% at rest while breathing room air. Chest examination revealed bilaterally fine crackles. His thorax computed tomography showed bilateral widespread ground-glass opacities and interlobular and intralobular septal thickening. His blood test revealed antinuclear antibody positivity. He had been using nitrofurantoin for a long time for urinary tract infection. He had a high score on Naranjo Adverse Drug Reaction Probability Scale. When he was a diagnosed, he had a respiratory failure due to lung damage. Patients using nitrofurantoin should be followed up closely for drug toxicity.