Purpose:The aim of our study was to examine whether left atrial dispersion and left atrial strain as measured by speckle tracking echocardiography and clinic paramaters are predictors for the development of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy. Methods: A total of 137 patients (70% male, mean age 49.6 ± 14.2 years) with HCM were included in the study. Patients’ clinical, electrocardiographic, 2D classic and speckle tracking echocardiographic (STE) data were collected. AF was searched by 12-lead electrocardiograms or 24-hour Holter recordings during follow-up period. Atrial dispersion was defined as the standard deviation of time to peak strain in 12 left atrial segments Results: During a follow-up period of 5 years 37 patients (16.9%) developed AF. At follow-up, the patients with occurrence of AF were older than in patients without AF. Atrial dispersion was observed to be higher in the AF developing group (61.4 ± 23.2 vs 43.1±15.8, p=<0.001). The multivariate in Cox regression analysis (including atrial dispersion, PALS, age, LA) atrial dispersion (msn) (HR 1.017, 95% CI: 1.001-1.03, p= 0.035) and age were found to be independent predictors of AF occurrence. In the ROC analysis atrial dispersion > 44.7 msn predicted occurrence of AF with 82.4% sensitivity and 64 % specificity. Conclusion: In patients with hypertrophic cardiomyopathy, atrial dispersion and age are predictive of the development of atrial fibrillation. Atrial dispersion measured by the speckle tracking-based method may provide further information in evaluating left atrial functions in patients with hypertrophic cardiomyopathy or other disease states