BACKGROUND: Bronchiolitis obliterans organizing pneumonia (BOOP) is a type of diffuse interstitial lung disease characterized by the pathology of fibroblastic plugs in the lumens of the respiratory bronchioles, alveolar ducts, and alveoli. The occurrence of BOOP in human immunodeficiency virus (HIV)-infected patients has rarely been described, and there have been no clinical case reports in Korea. CASE PRESENTATION: A 24-year-old female who had been diagnosed with HIV ten years prior was admitted due to a 1-year history of cough and sputum production and a 3-day history of fever. She had poor adherence to anti-retroviral therapy (ART) due to gastrointestinal troubles. At the time of admission, her CD4 T-cell count was 5 cells/mm(3). A hi...