Objectives This study used air plethysmographic parameters to evaluate the changes in venous hemodynamics after the surgical treatment of primary varicose veins. Methods We retrospectively analyzed 1756 limbs of 1620 patients who had undergone surgery for great saphenous vein (GSV) reflux from January 1996 to June 2009 at Samsung Medical Center. Venous hemodynamic changes were evaluated by performing air plethysmography preoperatively and 1 month postoperatively and assessing the venous volume (VV), the venous filling index (VFI), the residual volume fraction (RVF), and the ejection fraction (EF). Results Preoperatively, median (interquartile range) values were VV, 121.6 (94.7-160.6) mL; VFI, 4.8 (2.9-7.6) mL/s; RVF, 40.6% (29.7%-50.0%); and EF, 53.5% (44.3%-64.1%). Postoperatively, the median (interquartile range) values were VV, 90.6 (69.1-116.8) mL; VFI, 1.4 (0.9-1.9) mL/s; RVF, 28.4% (17.5%-38.7%); and EF, 65.2% (54.5%-77.2%). VV, VFI, and RVF were reduced 25.2%, 71.5%, and 29.9%, respectively; EF was increased 20.3%. The results were significant for all four variables ( P < .001). We compared the degree of hemodynamic changes according to the treatment modalities: the high ligation and stripping group , 1578 cases; the GSV valvuloplasty group, 124 cases; and the VNUS group (VNUS Medical Technologies Inc, San Jose, CA), 54 cases. The reduction of the VV, VFI, and RVF was greater in the GSV stripping group and in the VNUS group than in the valvuloplasty group ( P < .001), yet no difference was noted in the EF increase among the surgical modalities ( P = .157). Conclusion Our results show that the venous hemodynamic parameters of primary varicose veins were improved after surgical treatment.