Objective To determine whether changes in pulmonary vascular resistance (PVR) and changes in pulmonary artery compliance ( C pa ) are associated with changes in exercise capacity assessed either by changes in peak oxygen consumption ( V ′ O 2 ) or by changes in 6-min walk distance (6MWD) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing balloon pulmonary angioplasty (BPA). Methods Invasive haemodynamic parameters, peak V ′ O 2 and 6MWD were measured within 24 h, before and after BPA (interval 3.1±2.4 months) in 34 CTEPH patients without significant cardiac and/or pulmonary comorbidities, of whom 24 received at least one pulmonary hypertension-specific treatment. C pa was calculated according to the pulse pressure method: C pa =((SV/PP)/1.76+0.1), where SV is the stroke volume and PP is the pulse pressure. The resistance–compliance (RC)-time of the pulmonary circulation was calculated as the PVR and C pa product. Results After BPA, PVR decreased (562±234 versus 290±106 dyn·s·cm −5 ; p<0.001); C pa increased (0.90±0.36 versus 1.63±0.65 mL·mmHg −1 ; p<0.001); but RC-time did not change (0.325±0.069 versus 0.321±0.083 s; p=0.75). There were improvements in peak V ′ O 2 (1.11±0.35 versus 1.30±0.33 L·min −1 ; p<0.001) and in 6MWD (393±119 versus 432±100 m; p<0.001). After adjustment for age, height, weight and gender, changes in exercise capacity, assessed either by peak V ′ O 2 or 6MWD, were significantly associated with changes in PVR, but not with changes in C pa . Conclusions Contrary to what has been reported in CTEPH patients undergoing pulmonary endarterectomy, in CTEPH patients undergoing BPA, changes in exercise capacity were not associated with changes in C pa .