48 patients with knee osteoarthritis were randomized to receive either hyaluronic acid (HA) or placebo intra-articular injections. The purpose of this study was to investigate the effect of three intra-articular hyaluronic acid (HA) injections on pain and function in knee osteoarthritis patients over a 14 week period. The results of this trial indicated that both Intra-articular HA injections and placebo injections significantly improved both pain and function from baseline values. The only finding found to significantly favour the HA group compared to placebo was an improvement in WOMAC pain with walking from baseline to 14 weeks.