Balloon pulmonary angioplasty (BPA) has been reported to improve haemodynamics and functional capacity, with an acceptable risk, in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not candidates for pulmonary endarterectomy. However, right ventricular (RV) function, an important predictor in CTEPH, remains to be elucidated. We aimed to examine the impact of BPA on RV remodelling and dysfunction relative to haemodynamic improvements in patients with inoperable CTEPH. 20 consecutive patients with inoperable CTEPH who underwent BPA with cardiovascular magnetic resonance before and after BPA were retrospectively studied. BPA led to significant amelioration of the mean pulmonary arterial pressure, cardiac index and pulmonary vascular resistance (PVR), without death or major complications. Furthermore, BPA significantly ameliorated right-sided heart failure symptoms and signs, and exercise capacity. Cardiovascular magnetic resonance revealed a marked improvement in RV end-diastolic and end-systolic volume index, with concomitant improvements in RV ejection fraction, mass and interventricular septal bowing after BPA. Changes in RV volumes strongly correlated with changes in cardiac index and PVR. BPA induced RV reverse remodelling and improved systolic dysfunction safely by ameliorating haemodynamics in patients with inoperable CTEPH. Evaluating RV function with cardiovascular magnetic resonance may be effective for noninvasively monitoring BPA efficacy.