[Purpose]There is little known about mobilization with movement (MWM) which is used to treat lateral epicondylitis of the elbow and its effects on functional activities. The purpose of this study was to investigate the effects of the mobilization-with-movement technique on elbow pain and functional activities of subjects with lateral epicondylitis. [Methods] Ten subjects with lateral epicondylitis of the elbow were randomly divided into an experimental group (n=5) and a placebo control group (n=5). Therapeutic intervention for both groups included general therapy such as hot packs, transcutaneous electrical nerve stimulation, ultrasound therapy, and deep friction massage. The experimental group received MWM, whereas the placebo control group received sham MWM after general therapy. All subjects received therapeutic intervention every other day for 10 days. Pain and functional activities were assessed before and after the interventions using the patient-rated tennis elbow evaluation scale (PRTEE). [Results] Significant and clinically meaningful improvements in pain, special activity, and usual activity sub-domains were found post-intervention in the experimental group. [Conclusion] The results indicate that mobilization-with-movement has a positive effect on both pain and functional activities of patients with lateral epicondyltis.