A pharmaceutical composition for the treatment of osteoarthritis comprising piroxicam or pharmaceutically acceptable salt thereof and hyaluronic acid or pharmaceutically acceptable salt thereof at a specific ratio is provided. The composition generates synergistic effect on both anti-inflammatory and analgesic effects simultaneously. The pharmaceutical composition contains 0.25-10.0 wt % of piroxicam or its pharmaceutically acceptable salt and 0.5-5.0 wt % of hyaluronic acid or its pharmaceutically acceptable salt, wherein the weight ratio between piroxicam or its pharmaceutically acceptable salt and hyaluronic acid or its pharmaceutically acceptable salt is between 1:1 and 1:3.