106 patients with grade 1-3 knee osteoarthritis were randomized into two groups to examine the efficacy of hyaluronic acid and the potential differences that may be present based on the number hyaluronic acid injections provided. Patients received 3 injections of saline (placebo) once weekly followed by 3 injections of hyaluronic acid once weekly or they received 6 once weekly injections of hyaluronic acid. The purpose of this study was to compare the changes in pain, function and patient satisfaction between the placebo and hyaluronic acid injections at 3 weeks and then compared differences in the outcomes between 3 and 6 injections of hyaluronic acid at 6 and 12-week follow-ups. The results indicated that hyaluronic acid injections offered a significantly greater reduction in pain compared to placebo at 3 weeks. Results at 6 and 12-week follow-ups revealed there were no clinical differences between 3 and 6 once weekly hyaluronic acid injections for patients with knee osteoarthritis.