Background: cardiovascular complications are the leading mortality cause among children with chronic kidney diseases (CKD), being responsible for up to 30% of deaths. Left ventricle (LV) diastolic dysfunction is common and has been linked to poor cardiovascular outcomes. Echocardiographic assessment of diastolic function in CKD children is usually limited to spectral and tissue Doppler imaging, known to be less reliable techniques in pediatrics. Two-dimensional Speckle tracking echocardiography (2DST) evaluation of LA strain has recently been confirmed as a robust measure of diastolic function, in different clinical scenarios. Objectives: to investigate LA strain role in diastolic function assessment of children at different stages of CKD, comparing it with standard echocardiographic parameters. Methods: From February 2019 to July 2022, 55 consecutive pediatric CKD patients without cardiovascular symptoms and 55 healthy volunteers were evaluated by standard and 2DST echocardiograms. Clinical data were collected from medical records by the attendant physician. Results: patients and controls had similar age [9.78 (0.89 – 17.54) years vs. 10.72 (1.03 – 18,44) years; p = 0.41] and gender (36M:19F vs. 34M:21F; p = 0.84). The median duration of the disease was 8.1 (0.83 - 17.5) years. There were 7 (12.8%) CKD stage I, 4 (7.3%) CKD stage II, 12 (21.8%) CKD stage III, 2 (3.6%) CKD stage IV and 30 (54.5%) CKD stage V patients. Standard echo reveled preserved (≥ 55%) LV EF in all of them. Although average E/e’ was higher in CKD [6.99 (4.75 – 14.20) vs. 6.38 (3.88 – 11.11); p = 0.009], it was above normal limits in only one individual. Comparing CKD and controls, LA reservoir strain was lower (48.22 ± 10.62% vs. 58.52 ± 10.70%; p < 0.0001) and LA stiffness index was higher [0.14 (0.08 – 0.48) % ^-1 vs. 0.11 (0.06 – 0.23) % ^-1; p < 0.0001]. LV hypertrophy was associated with lower LA reservoir strain (42.05 ± 8.74% vs. 52.99 ± 9.52%; p < 0.0001), higher LA stiffness index [0.23 (0.11 – 0.48) % ^-1 vs. 0.13 (0.08 – 0.23) % ^-1; p < 0.0001) and filling index (2.39 ± 0.63 cm/s x % ^-1 vs. 1.74 ± 0.47 cm/s x % ^-1; p = 0.0001). Uncontrolled hypertension was associated with lower LA reservoir strain (41.9 ± 10.6% vs. 50.6 ± 9.7; p = 0.005). CKD stage showed negative correlation with LA reservoir strain ( r = - 0.37; p = 0.006) and conduit strain ( r = - 0.28; p = 0.0035), besides positive correlation with LA stiffness index (r = 0.48; p = 0.0002). E/e’ showed inferior accuracy in differentiating CKD patients from controls (AUC = 0.64), when compared with LA reservoir strain (AUC = 0.75) and LA stiffness index (AUC = 0.73). LA reservoir strain showed the best accuracy in differentiating dialysis form non dialysis patients (AUC = 0.77). Conclusions: LA strain parameters, especially reservoir strain and stiffness index, showed better accuracy than conventional E/e’ ratio concerning diastolic evaluation in pediatric CKD population. Since diastolic dysfunction bears strong prognostic value in CKD, incorporation of LA strain in routine echocardiographic evaluation of this particular pediatric population seems to be an appropriate strategy