OBJECTIVE Acute pericarditis is a minor complication following atrial fibrillation (AF) ablation procedures. The aim of the study was to evaluate the incidence and clinical aspects of pericarditis following cryoballoon (CB) ablation of AF investigating a possible association with procedural characteristics and a possible relationship with post-ablation recurrences. METHODS Four hundred fifty consecutive patients (male 73%, age 59.9 ± 11.2 years) with drug-resistant paroxysmal AF who underwent CB ablation as index procedure were enrolled. Exclusion criteria were any contraindication for the procedure including the presence of intracavitary thrombus and uncontrolled heart failure and contraindications to general anesthesia. RESULTS Acute pericarditis following CB ablation occurred in 18 patients (4%) of our study population. Pericardial effusion occurred in 14 patients (78%) and was mild/moderate. The total number of cryoapplications and the total freeze duration were significantly higher in patients with pericarditis compared with those without (respectively, p = 0.0006 and p = 0.01). Specifically, the number of applications and freeze duration in right inferior pulmonary vein were found significantly higher in patients with pericarditis (p = 0.007). The recurrence rate did not significantly differ between the two study groups (respectively, 16.7 vs 18.1%; p = 0.9). CONCLUSIONS The incidence of acute pericarditis following CB ablation in our study population accounted for 4% and was associated with both total freezing time and number of cryoapplications. The clinical course was favorable in all these patients and the occurrence of acute pericarditis did not affect the outcome during the follow-up period.