Objectives To analyze the effect of disease-modifying antirheumatic drugs (DMARDs) on the outcome of interstitial lung disease secondary to rheumatoid arthritis (RA-ILD). Patients and methods We performed a multicenter, prospective, observational study of patients with RA-ILD receiving DMARDs between 2015 and 2017. The patients were assessed using high-resolution computed tomography and pulmonary function tests at baseline and at 24 months. The radiological assessment was centralized. The main outcome measure at 24 months was changed in lung function (improvement, stabilization, worsening, or death). We recorded the 28-joint Disease Activity Score 28 (DAS28) and adverse events. A logistic regression analysis was performed to identify factors associated with worsening of ILD. Results After 24 months, lung disease was stabilized in 40 patients (57.1%), improved in 8 (11.4%), and worse in 21 (30.0%). One patient (1.4%) died. The factors associated with worsening of ILD in the multivariate analysis were treatment with abatacept, tocilizumab, or rituximab (OR, 0.102 95%CI, 0.015–0.686), DAS28 (OR, 1.969 95%CI, 1.005–3.857), and smoking (OR, 6.937 95%CI, 1.378–4.900). During follow-up, 30 patients (42.9%) experienced an adverse event, which was severe in 12 cases (17.1%). Conclusions Lung function is stable and inflammatory activity well controlled in most patients with RA-ILD receiving treatment with DMARDs. Non-anti-TNF DMARDs reduce the risk of worsening of lung disease in 90% of patients. The inflammatory activity of RA and smoking, on the other hand, are associated with worsening. Key Points • We have performed prospectively evaluated lung and joint function in patients with RA-ILD receiving treatment with various DMARDs. • In our study, the lung function is stable and inflammatory activity well controlled in most patients with RA-ILD receiving treatment with DMARDs. • Neither csDMARDs nor anti-TNF agents were associated with a significant risk of worsening of lung disease, whereas non-anti-TNF bDMARDs could reduce the risk of worsening of lung disease. • Smoking and poor control of joint involvement were the main factors associated with worsening of lung disease.