Introduction: Pulmonary vein (PV) isolation using cryoballoon ablation (CBA) is a common therapy for patients with drug refractory paroxysmal atrial fibrillation (PAF). However, initial CBA is successful in only 70-80% of patients. The role of an atypical left common PV (LCPV) and PV anatomical indices on CBA outcomes remains unclear. Methods and Results: We followed 80 patients (age 60.7 ± 9.7, 31 % women) with PAF undergoing CBA for one-year post-procedure for the development of recurrent atrial arrhythmias (AA). Recurrence was assessed by documented AA on EKG or any form of long-term cardiac rhythm monitoring. The presence of an LCPV and individual PV diameters were evaluated using cardiac CT. Based on the maximum and minimum PV ostial diameters, the eccentricity index (EI), ovality index (OI), and PV ostial area (PVA) were calculated for all the veins. A multivariable cox-proportional hazard model assessed whether the presence of an LCPV or PV anatomic indices (EI, OI and PVA) predicted recurrence of AA following CBA. After one year follow up, 19 (23.7%) participants developed recurrence of AA. On multivariable regression, the presence of an LCPV did not predict the recurrence of AA (p = 0.38). Among the PV anatomical indices, on univariate analysis, only the area of the left inferior PV showed a trend towards predicting recurrence, though this result was not significant on multivariate analysis (p = 0.09). Conclusion: In patients with PAF, neither the presence of an LCPV nor individual PV anatomical indices predicted recurrence of AA following CBA.