Purpose of the study. To evaluate the effectiveness of cryoballoon ablation of the pulmonary veins in young patients (from 18 to 45 years old) with paroxysmal and persistent forms of AF, as well as to identify factors influencing the development of relapse in the postoperative period. Material and methods. The follow-up period ranged from 19 to 52 months (mean follow-up period was 34±12 weeks). A total of 54 patients who met the selection criteria were included in the study. Depending on the form and duration of AF paroxysms, documented by ECG and Holter monitoring, patients were divided into two groups. The first group included 40 patients with paroxysmal AF (74%), and the second included 14 patients with persistent AF (26%). A statistically significant difference was revealed when analyzing the arrhythmological history of AF for 23.3±2.8 weeks. in patients with paroxysmal AF and 43.7±3.68 weeks. with persistent AF. Results. In 19 patients, recurrence of arrhythmia was documented during the observation period. We analyzed the relapse group depending on the form of AF; it was found that in patients with a persistent form, the frequency of relapse as a percentage was higher than in patients with paroxysmal form of AF (9 out of 14 (64.3%) and 10 out of 35 (25%) patients respectively). The odds of relapse in the group with the persistent form were 5.4 times higher compared with the paroxysmal group, the differences in odds were statistically significant (OR=1.594; 95% CI: 1.462–19.946)) (p<0.020). When conducting a univariate Cox regression analysis, the persistent form of AF (OR: 5.53; CI: 2.57–11.87), the presence of diabetes (OR: 3.316; CI: 1.093–10.055), the presence of hypertension (OR: 2.30; CI: 1.14–4.63), as well as PALS ≤24.7 (RR: 2.44; CI: 1.12–5.29) and IOLP ≥54.9 ml/m2 (RR: 11.284; CI : 4.145–30.717) showed the strongest association with the development of recurrent AF. As a result of multivariate Cox analysis, the predictors that had an independent effect on the risk of relapse of AF after cryoballoon isolation of the PV were persistent form of AF, the presence of diabetes mellitus and an IOLP value ≥54.9 ml/m2 . These predictors included in the model were characterized by a direct relationship with the risk of AF recurrence. Thus, the persistent form of AF and the presence of diabetes mellitus led to an increase in the risk of relapse of AF by 5.53 and 3.32 times, respectively. At the same time, an IOLP value ≥61.9 ml/m2 also led to an 11.3-fold increase in the risk of AF recurrence. Freedom from recurrence of AF after cryoballoon isolation of the PV during the observation period after cryoballoon isolation of the PV was 75.1% for the group of patients with paroxysmal form and 37.0% for the group of patients with persistent form of AF. Freedom from AF recurrence after cryoballoon isolation of the PV during the observation period after cryoballoon isolation of the PV was 69.4% for the group of patients with IOLP ≥61.9 ml/m2 and 23.3% for the group of patients with IOLP ≤61.9 ml/m2. Conclusion. Cryoablation in young patients is effective and safe, as demonstrated in our study. All patients had a smooth recovery period after CBA.