Aim: to assess and evaluate the Left Atrial (LA) dysfunction by two-dimensional speckle tracking echocardiography (2DSTE) in patients with diastolic heart failure (DHF) and systolic heart failure (SHF). Materials and methods: The study included 74 patients with DHF, 26 patients with SHF, and 50 normal matched subjects. The LA phasic functions, LA volume index and E/e~ were evaluated by conventional echocardiography.The2DSTE used to evaluate both the left ventricular global strain (LVGS) and The Left Atrial Global Strain (LAGS) and reevaluate the LA phasic functions through Peak-atrial longitudinal strain (PALS), peak-atrial contraction strain (PACS), and PALS-PACS which reflecting LA reservoir, pump, and conduit function, respectively. Results: The LVGS was -19.54±1.42 % in controls, -18.66±1.15 % in DHF and -14.72±1.97 % in SHF (P-value <0.0001); LAGS was 52.62±6 %in controls,37.86±4.59 in DHF and 21±5.37 in SHF (P-value <0.0001); The PALS was 49.9±4.83 in controls, 33.26 ±4.82 in DHF and 19.69±5.55 in SHF(P-value was<0.0001);The PACS was 20.19±2.25 in controls, 12.47±2.29 in DHF and 8.35±2.71 in SHF (P-value <0.0001); The PALS-PACS was29.57±4.02 in controls, 20.76±3.8 in DHF and 11.35±3.14 in SHF (p-value <0.0001). Conclusion: LA phasic function was worse in SHF compared with those with DHF. Early LA dysfunction in Heart failure can be detected accurately and easily by speckle tracking technique more than conventional echocardiography suggesting that The LA myocardial deformation analysis by 2-D STE could be a promising tool to better understand of heart failure and its classification. Key words: Speckle tracking; systolic heart failure; diastolic heart failure; left atrial dysfunction.