Smoking is important as a disease development and exacerbation factor in rheumatoid arthritis (RA) as well as in smoking-related interstitial pneumonia (SR-IP), including desquamative interstitial pneumonia (DIP), and respiratory bronchiolitis-associated with interstitial lung disease (RB-ILD). Case 1: A 64-year-old man who had stopped smoking 7 years previously. A medical check-up CT showed a right middle lobe nodular opacity and interstitial pneumonia. The right middle lobe resection specimen revealed respiratory bronchiolitis with lymphoid follicles and a DIP pattern. The patient developed RA 2 months after the operation. Case 2: A 68-year-old man had been diagnosed with RA 10 years earlier. IP developed 2 years later and he stopped smoking. The follow-up CT showed a nodule in the upper right lobe. The upper right lobe specimen revealed alveolitis with lymphoid follicles and an RB pattern. Cases with RA and SR-IP reactions are rare, and an RB pattern may have a more favorable prognosis than a DIP pattern.