We conducted an anatomical study of arthroscopic surgery for lateral epicondylitis. Currently, the pathogenesis suggests that lateral epicondylitis is caused by extra-articular lesions or intra-articular lesions. We anatomically and histologically examined the relationship between extensor carpi radialis brevis (ECRB), articular capsules, and the lateral collateral ligament complex (LCLC). In addition, we examined the number and location of synovial fringes. This study will be useful for less-invasive treatment of lateral epicondylitis.