Background: The limitation of aortic size-based criteria is gradually recognized in the prediction of aortic events especially in bicuspid aortic valve (BAV) cohorts, while most aortic events happen in patients with proximal aortic diameters 50 mm. Circulating microRNAs (miRs) have been addressed as a novel tool to improve risk stratification in patients with different aortopathies. We aimed to elucidate the correlation between peripheral whole blood and aortic tissue miRs in order to prove the potential availability as a biomarker in the clinical routine. Methods: All patients who received elective aortic valve repair/replacement \pm proximal aortic replacement to BAV disease (n = 65, 2013–2018) were prospectively included. The expression of 10 miRs (miR-1, miR-17, miR-18a, miR-19a, miR-20a, miR-21, miR-106a, miR-133a, miR-143 and miR-145) was analyzed in the intraoperatively acquired aortic tissue as well as in the peripheral blood before the surgery. Results: We found a significant correlation between circulating miRs in the peripheral blood and aortic tissue levels of miR-21 (r = 0.293, p = 0.02), miR-133a (r = 0.43, p = 0.02), miR-143 (r = 0.68, p 0.001), and miR-145 (r = 0.68, p 0.001). Further, the multivariate logistic regression analysis revealed an association between blood and aortic tissue miR-143 levels each other (Odds Ratio [OR] 1.29, 95% Confidence Interval [CI] 1.11–1.67, p = 0.02; OR 1.36, 95% CI 1.19–2.01, p = 0.03, respectively) and a blood/aortic miR-143 level to dilated aorta (OR 3.61, 95% CI 1.62–9.02, p = 0.01; OR 2.92, 95% CI 1.81–7.05, p = 0.02, respectively). Conclusions: Our study demonstrates a significant correlation between peripheral whole blood and aortic tissue miRs, confirming the hypothesis that circulating miRs may reflect remodeling processes in the proximal aorta in bicuspid aortopathy patients.