Aim of the work: Detection of serum and synovial fluid level of Vascular Endothelial Growth Factor (VEGF) in patients with knee osteoarthritis (OA) and to determine its relation to radiological severity and function status. Patients and methods: Thirty OA patients and thirty controls were included. Function status was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Knee pain evaluated using the Visual Analogue Scale (VAS). Serum and synovial fluid level of VEGF were measured. Kellgren-Lawrence grading scale (KL) used to assess radiological severity. Results: The mean of patients’ age was 50.33 ± 5.3 years (20 females and 10 males) with disease duration of 7.03 ± 2.12 years. Mean synovial fluid VEGF of OA patients was 964.1 ± 396.72, mean serum... VEGF of OA patients was 219.1 ± 96.95. No difference between serum VEGF of patients and control groups (p=0.787). Significant positive correlation between serum and synovial VEGF in OA patients (r=0.58, p=0.001). Significant positive correlation between the synovial fluid VEGF and patients’ age, disease duration, inactivity stiffness, ESR, VAS, WOMAC and KL grade scale (p‹0.0001,p=0.029,p‹0.0001,p‹0.0001,p=0.00 3,p‹0.0001,p‹0.0001). Significant positive correlation between serum VEGF and patients’ age, inactivity stiffness, WOMAC, ESR and KL grade scale (p‹0.0001, p=0.005, p=0.001, p=0.001,p=0.010). Synovial fluid VEGF was the significant predictors for determining the function status (p‹0.0001); while for determining severity; synovial fluid VEGF, patients’ age and VAS were significant predictors (p‹0.0001,p=0.001 and p=0.029 respectively). Conclusion: Serum and synovial fluid VEGF correlated with the clinical features, functional status and radiological features of Knee OA. Synovial VEGF can predict both functional impact and radiological severity in patients with knee OA.