Abstract Background and Aims The renal dysfunction is known to be the most important predictor of outcome in patients with atrial fibrillation (AF). At the same time, assessment of the functional state of the kidneys is an integral part of the protocol when selecting the dose of oral anticoagulants. The prognostic role of the functional state of the kidneys during treatment with oral anticoagulants on a possible worsening of the cardiac prognosis during the treatment of AF in patients with concomitant comorbid background, in particular with COPD, has not been sufficiently studied. The aim of the study was to evaluate the prognostic role of renal dysfunction in terms of possible cardiovascular events and bleeding in patients with COPD and AF treated with oral anticoagulants. Method 56 COPD patients with CHF and AF who received oral anticoagulants were examined. Renal function (creatinine level and estimated glomerular filtration rate - eGFR) was assessed at baseline and follow-up. The functional state of the kidneys was calculated using the CKD-EPI-2011 formula. At baseline, the risk of bleeding was assessed using the HAS-BLED scale. Worsening of the functional state of the kidneys was detected when the level of creatinine increased or eGFR decreased by at least 20%. Results In addition to standard treatment for COPD in the presence of AF, patients received oral anticoagulants during six months of observation. Worsening of the functional state of the kidneys was observed in 18.3% of patients. In patients with renal dysfunction, the frequency of episodes of CHF decompensation and non-major bleeding (MB) was significantly higher. With a reduced glomerular filtration rate, there was no effect on the incidence of bleeding and stroke. The oral anticoagulants used did not have a significant effect on the observed renal dysfunction and did not affect the occurrence of new cardiovascular events in patients with COPD. It turned out that predictors of renal dysfunction in patients with COPD are age, female gender, and lower hemoglobin levels. In multivariate analysis, renal dysfunction was identified as an independent predictor of non-major bleeding (OR 2.04, 95%, p < 0.05). Conclusion In patients with COPD and atrial fibrillation, the presence of renal dysfunction was an additional exacerbating factor associated with a poor mid-term cardiovascular prognosis and the risk of bleeding. However, oral anticoagulants did not affect the degree of deterioration of renal function or the incidence of cardiovascular events.