Patients with symptomatic osteoarthritis of the knee are typically obese and relatively less active and may be associated with cardiovascular deconditioning and increased risk of heart disease. Purpose of this study was to evaluate the impact of the total knee arthroplasty upon cardiovascular status of the patient, as indicated by assessment of the endothelial function and correlation of the same with the functional outcome. Endothelial function has been found to correlate with the cardiovascular health of an individual closely and therefore was chosen as a noninvasive means to study the same. This study was conducted prospectively in 34 patients of advanced Osteoarthritis of knee joint (11 males, 23 females) who underwent unilateral (25) or bilateral (9) total knee arthroplasty at a mean age of 59.2 + 9.7 years (range 40–77 years). All the patients underwent preoperative assessment of endothelial function by the method of flow mediated dilatation (FMD). We report the results at 2 to 3.5 years (mean, 3.0) follow-up. The reassessment of the endothelial function and functional outcome in terms of Knee society score were performed at follow up. We noted excellent improvement in Knee society score (mean 102.3 + 22.9 at 6 months, 152.5 + 19.8 at 18 months and 174.4 + 17.3 at 42 months compared to 65.4 + 30.3 preoperatively). There was good improvement in endothelial function at 6 months (29.98 + 19.28%) and excellent improvement (69.87 + 35.57%) at 18 months and (85.65 + 26.14%) at 42 months respectively. Significant improvement in endothelial function can result following total knee arthroplasty.