Background: The purpose of this study was to determine the effects of massage, stretching exercise, and scapular stabilization exercise in patients with upper trapezius myofascial pain syndrome (MPS). Methods: Twenty-three female patients with upper trapezius MPS were randomly allocated to three groups: massage, stretching exercise, and scapular stability exercise groups. Therapeutic intervention for all groups included general therapy such as hot pack, transcutaneous electrical nerve stimulation and ultrasound. Patients in the massage group (n=8), stretching group (n=7), and stabilization exercise group (n=8) received their respective therapy program after general therapy for 15 minutes. Therapeutic intervention for each group was performed three times per week for six weeks. All groups were tested four times: prior to the test, at three weeks, at six weeks, and at nine weeks. Results: Pain levels decreased significantly in the stretching and stabilization exercise groups over time (p<.05). The rate of change in pain level was significantly different among all groups (p<.01), and the stability exercise group experienced the lowest pain level. Pressure-pain level increased significantly in the stabilization exercise group over time (p<.05). The rate of change in pressure-pain level was significantly different among all groups (p<.01), and the stability exercise group had the highest pressure-pain level. The level of upper-extremity stability increased significantly in the stability exercise group over time (p<.05). The rate of change in the upper-extremity stabilization level was significantly different among all groups (p<.01), and the stability exercise group had the highest upper-extremity stability level. Conclusions: Scapular stabilization exercises proved to be the most effective therapy for MPS patients.