43 female patients with knee osteoarthritis were randomly assigned into 1 of 2 groups to investigate the effect of adding nonsteroidal anti-inflammatory drugs (NSAID) to intra-articular (IA) hyaluronic acid (HA) injection therapy on pain relief. Those placed in the nonsteroidal anti-inflammatory drug group were given 3 weekly IA injections of hyaluronic acid (HA) with 30 mg of ketorolac (an NSAID), followed by two weeks of only IA HA injections, while those placed in the HA group received only IA HA injections for five weeks. Results demonstrated that those who received NSAID therapy along with HA had quicker analgesic onset than those who received only HA. Some patients in the NSAID group developed focal post-injection knee pain, while no one in the HA only group experienced this complication. No serious complications were experienced in either group.