The objective of this work was to assess the predictive value of pre-procedural N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in patients undergoing atrial fibrillation (AF) ablation. Seventy-three consecutive patients with AF (paroxysmal n = 49, persistent n = 24) and preserved left ventricular (LV) systolic function (LV ejection fraction > 45%) were prospectively enrolled in this study. All of the enrolled patients underwent catheter ablation after a measurement of their plasma NT-proBNP levels, and an echocardiographic examination with assessment of their LV diastolic function and left atrial(LA) volume. Patients with AF recurrence at 3 months had more persistent AF (P = 0.001), a higher LA volume index (P = 0.002), lesser decelerating times (DT) of mitral inflow (P = 0.014), and higher NT-proBNP levels (P < 0.001), when compared with patients with sinus rhythm restoration. The baseline log NT-proBNP correlated significantly with age (r = 0.26, P = 0.025), LA volume index (r = 0.41, P = 0.001), E/E’ (r = 0.34, P = 0.007), DT (r = −0.34, P = 0.007), and E (r = 0.25, P = 0.04). The log NT-proBNP (HR 7.76, 95% CI 2.95–20.39, P < 0.001) was an independent predictor of AF recurrence. The measurement of NT-proBNP added incremental predictive value to standard indexes of LA size or diastolic function, including LA volume index and DT (P = 0.02). This study suggests the clinical utility of the level of NT-proBNP as an integrating marker of various risk factors, and as an incremental predictive marker for AF catheter ablation.