Background Delayed catheter ablation (CA) has been associated with higher rates of atrial fibrillation (AF) recurrence. Low-voltage zones (LVZs) are established predictors of AF recurrence after CA. Data on LVZ assessment in relation to diagnosis-to-ablation time (DAT) remain limited. This study aimed to evaluate the extent of left atrial (LA) LVZs, bipolar voltage, and the outcomes of voltage-guided CA in patients with persistent AF, classified according to DAT. Methods We consecutively enrolled 350 patients with persistent AF undergoing their first voltage-guided CA. Patients were classified according to DAT into two groups: DAT ≤1 year ( n = 131) and >1 year ( n = 219). LA voltage mapping was performed during sinus rhythm. LVZs were defined as regions with a bipolar voltage <0.5 mV. Results Patients with DAT >1 year exhibited lower LA bipolar voltage ( p < 0.01) and larger LA and indexed LA volumes ( p < 0.01). LVZs were more frequent in this group (43% vs. 28%, p = 0.01), particularly moderate LVZs ( p = 0.04). Recurrence of atrial tachyarrhythmias (ATs) after a single procedure occurred more often in patients with DAT >1 year (log-rank p = 0.05). Multivariable analysis revealed that female sex ( p < 0.001), indexed LA volume ≥48 mL/m 2 ( p = 0.008), age ≥60 years ( p < 0.05), and P-wave duration ≥150 ms ( p < 0.001) were independently associated with the presence of LVZs. A history of paroxysmal AF was associated with a lower likelihood of LVZs, whereas DAT was not an independent predictor. Conclusion Patients with persistent AF and a longer DAT displayed more extensive LA substrate remodeling. Despite a tailored ablation targeting LVZs, a longer DAT was associated with a higher rate of AT recurrence. Early ablation within the first year after AF diagnosis could optimize AF CA outcomes.