Objectives: To assess the correlation between left atrial (LA) longitudinal strain and occurrence of atrial fibrillation (AF) in patients with dilated cardiomyopathy (DCM). Methods: 100 patients with DCM were evaluated. Conventional and speckle tracking echocardiography were done to evaluate LA diameters, volumes and longitudinal strain. Results: Left atrial dimensions and volumes were significantly greater in AF group. LA longitudinal strain and LA emptying fraction were significantly lower in AF group. LA longitudinal strain and LA minimal volume are independent predictors for AF presence. ROC curve showed that LA longitudinal strain cut-off value <11.1% can predict the presence of AF in DCM patients with 96% sensitivity and 95.3% specificity (AUC 0.982, 95% CI 0.959–1.0, P < 0.001) Conclusion: Left atrial longitudinal strain was significantly reduced in AF in the setting of DCM. LA longitudinal strain and LAVmin are independent predictors for AF occurrence in this group of patients with LA strain values <11.1% can be used to predict AF in DCM.