OBJECTIVE Chronic venous disease (CVD) is a prevalent pathology, and endothelial dysfunction is recognized as a core of its physiopathology. Flow-mediated dilation (FMD) is one of the most widely used tests for evaluating endothelial function. The aim of this study is to evaluate the influence of varicose vein (VV) surgery on FMD. METHODS A prospective study with patients with superficial CVD and saphenous incompetence on Doppler ultrasonography that were proposed for VV surgery. The FMD test was performed before and 6 months after the procedure. The operator performing the post-operative evaluation was blinded to the pre-operative result. RESULTS A total of 42 patients were included in the analysis. The median pre-operative percent change of FMD was 4.20% (±1.30) and the post-operative was 4.56% (±1.25) (p = 0.819). CONCLUSIONS Our findings do not corroborate the presence of an overall endothelial dysfunction prone to modulation by surgery. Nevertheless, further studies are needed to confirm our findings.