20 patients with bilateral knee osteoarthritis were administered two intraarticular injections of Variofill in the right knee and two intraarticular injections of Hylan G-F 20 in the left knee. Patients were assessed for treatment response on a Visual Analog Scale for pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) after 3 and 6 months. Comparative efficacy was assessed using percent improvement from baseline after 6 months. Results demonstrated significantly greater improvement for VAS pain, WOMAC Pain, and WOMAC Function scores in the Variofill group compared to the Hylan G-F 20 group, with no significant differences between groups in improvement in WOMAC Stiffness.