BACKGROUND Interstitial lung disease, also known as diffuse parenchymal lung disease, is a group of diseases that affects the interstitium of the lungs and can lead to progressive fibrosis of the lungs. The potential causes of interstitial lung disease are broad and includes infection, malignancy, autoimmune/connective tissues diseases, inhaled substances, and certain medications. One of the medications that can cause interstitial lung disease is nitrofurantoin. CASE REPORT A 88-year-old man with recurrent urinary tract infections was treated with long-term nitrofurantoin prophylactic therapy. He took 100 mg of nitrofurantoin on a daily basis for over 10 years as prophylactic therapy for recurrent urinary tract infections, and subsequently developed chronic respiratory failure requiring supplemental oxygen. Chest radiography and high-resolution computed tomography imaging were performed and revealed pulmonary fibrosis consistent with interstitial lung disease. CONCLUSIONS Although nitrofurantoin is one of the most commonly used antibiotics in the treatment of urinary tract infections and is often considered a relatively safe medication, long-term use can lead to the development of interstitial lung disease.