AIMS: Reports using two-dimensional echocardiography have indicated that radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) results in a reduction in the left atrial (LA) size. Furthermore, the effect of pulmonary vein isolation (PVI) on right atrial (RA) anatomical remodelling has not been studied. Three-dimensional echocardiography (3DE) allows us to more precisely quantify atrial volume. Our aim was to assess the effect of PVI on biatrial anatomical remodelling using real-time 3DE. METHODS AND RESULTS: We prospectively studied 91 patients (age 59 +/- 8 years, 79 males) referred for RFCA of paroxysmal (n = 79) or chronic (n = 19) AF. Left atrial and RA volumes were measured using real-time 3DE at baseline and after 6 months of follow-up. Data on AF recurrences were also collected. Left atrial volume was significantly reduced at follow-up when compared with baseline (51 +/- 16 vs. 60 +/- 21 mL, P < 0.001). The same occurred with RA volume (43 +/- 17 vs. 50 +/- 20 mL, P = 0.001). The reduction in the LA volume was more marked in patients with chronic than in those with paroxysmal AF (17 +/- 16 vs. 6 +/- 17 mL, P = 0.017). Patients with AF recurrence (23%) showed similar atrial volume reduction compared with those who were seemingly cured. CONCLUSION: Three-dimensional echocardiography shows evidence of biatrial anatomical reverse remodelling after RFCA for AF. A reduction in the atrial volume occurs despite recurrence of AF.