A 66-year-old man, a 40-year smoker, was diagnosed with rheumatoid arthritis in 2018. He was treated for one year with methotrexate, and, later in 2020, he was diagnosed with interstitial pulmonary fibrosis. In 2022, treatment with nintedanib was initiated, with clinical improvement being indicated but without showing a functional or imaging benefit. The evolution of the disease was rapidly progressive and unfavorable, with death occurring due to pulmonary thromboembolism. Following the autopsy, triple lesions of the RA at the lung level were confirmed: interstitial, of the NSIP type with a fibrosing character at the level of the lower airways of the bilateral bronchiectasis type, and vascular damage due to pulmonary thromboembolism secondary to chronic inflammation.