To compare the effects of dry needling and physiotherapy in treatment of myofascial pain syndrome, a randomized controlled trial was performed on 28 patients with myofascial pain syndrome (MPS) of upper trapezius muscle in the Physical Medicine and Rehabilitation Center of Shohadaye Tajrish Hospital from April 2009 to April 2010. After matching the age, sex, duration of symptoms, pain severity, and quality of life measures, subjects were randomly assigned into two subgroups of case (dry needling) and control (physiotherapy). One week and 1 month after receiving standard therapeutic modalities, outcomes and intragroup and intergroup changes in pain severity, pressure pain of trigger point (TP), and quality of life measures were evaluated and compared. After 1 month, both the physiotherapy and dry needling groups had decreased resting, night, and activity pain levels (p<0.05). Pressure pain threshold of TP and some scores of quality of life (SF-36) were improved (p<0.05). Overall results were similar in both groups. It seems that both physiotherapy modalities and dry needling have equal effect on myofascial pain of the upper trapezius muscle.