We researched 3 patients diagnosed as Lateral epicondylitis (Tennis elbow). We considered it as tendinosis including irregular collagen fiber's pattern. So, acupuncture therapy and musculotendinous releasing manual therapy were used to treat the patients. We measured their pain and functional disorder by visual analogue scale (VAS), Patient-Rated Tennis Elbow Evaluation (PRTEE), and a dynamometer before and after treatment. As a result, VAS and PRTEE significantly reduced and grasping power was also improved. Therefore, we conclude that the acupuncture therapy with musculotendinous releasing manual therapy is an effective way to treat Lateral epicondylitis. But there are limits on this study due to insufficient number of cases, absence of control group and absence of follow-up after last treatment. Further studies will be needed.