The gold standard for assessing pressure gradients (PG) across coarctation involves measurements obtained through cardiac catheterization or surgical intervention. There has been ongoing discussion regarding the accuracy of non-invasive methods for estimating these gradients. This study sought to establish the correlation and agreement between the systolic blood pressure (SBP) gradient between the upper and lower extremities, as well as, the mean and maximum PG derived from echocardiography, in comparison to the peak-to-peak pressure gradient obtained from either cardiac catheterization or surgery. We conducted a retrospective study on patients < 18 years diagnosed with coarctation at Chiang Mai University Hospital from 2011 to 2022. The study involved the measurement of the SBP gradient between the upper and lower extremities, mean and maximum PG using echocardiography, peak-to-peak pressure gradient obtained from cardiac catheterization, and pressure gradient recorded during surgical procedures. The Spearman's correlation and Bland-Altman analysis were employed to assess correlation and agreement. Fifty-four patients with aortic coarctation were enrolled. The mean PG measured by echocardiography showed a significantly moderate correlation (r = 0.78, p < 0.001) and the highest level of agreement according to Bland Altman plots, in comparison to the peak-to-peak pressure gradient measured during both cardiac catheterization and surgical procedure. The max PG demonstrated a notable overestimation compared to the gold standard (mean difference + 13.14 with a slope of biases + 0.64, p < 0.001). The mean PG obtained through echocardiography has more potential to be applied in practical application in predicting pressure gradient in patients with coarctation.