120 patients with symptomatic knee osteoarthritis were randomized to receive intra-articular (IA) injections of platelet rich plasma (PRP), hyaluronic acid (HA) or corticosteroid for the treatment of pain and improvement of function. Outcomes of interest included the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, Visual Analog Scale (VAS) for pain and adverse events. Follow up was performed at 3, 6. 9 and 12 months. The results of the study found significant improvements from pre-treatment scores in both WOMAC and VAS pain outcomes in all three groups. Moreover at 6, 9 and 12 months, the PRP group showed significantly favourable WOMAC scores compared to both the hyaluronic acid and corticosteroid injection groups. There were no significant differences in adverse events between the three groups.