Aim: We aimed to evaluate the effect of echocardiographically demonstrated right ventricular dysfunction (RVD) on time in therapeutic range (TTR) in heart failure (HF) patients receiving warfarin therapy. Methods: A total of 893 consecutive HF patients were included and classified into 4 different subgroups: HF with preserved ejection fraction (HFpEF) without RVD (n = 373), HF with reduced EF (HFrEF) without RVD (n = 215), HFpEF with RVD (n = 106) and HFrEF with RVD (n = 199). Groups were compared according to baseline, demographic and clinical data and the characteristics of warfarin therapy. Results: Presence of RVD yielded lower median TTR values both in HFpEF and HFrEF patients. RVD, current smoking, New York Heart Association functional class III/IV, hypertension, diabetes mellitus, pulmonary disease, prior transient ischemic attack or stroke, chronic kidney disease (CKD) stage 4/5 and CKD stage 3 were found to be independent predictors of poor anticoagulation control in multivariate logistic regression analysis. Conclusions: The present study demonstrated that presence of RVD in HF increases the risk for poor anticoagulation.