Background: Chronic lateral epicondylitis (CLE), or “tennis elbow,” is produced by a degenerative mechanism of the extensor tendon. (CLE) can produce a great monetary and social costs due to lost workdays. Ozone molecules have anti-inflammatory, analgesic, anti-oxidant, immune-modulatory effect, and became an effective treatment tool for musculoskeletal disorders. Objectives: This study was done to investigate the effect of ozonated gel phonophoresis on pain intensity, wrist range of motion, hand grip strength and hand activities in patients with chronic lateral epicondylitis.