OBJECTIVE: To investigate the remote effect of dry needling on the irritability of a myofascial trigger point in the upper trapezius muscle. DESIGN: Thirty-five patients with active myofascial trigger points in upper trapezius muscles were randomly divided into two groups: 18 patients in the control group received sham needling, and 17 patients in the dry-needling group received dry needling into the myofascial trigger point in the extensor carpi radialis longus muscle. The subjective pain intensity, pressure pain threshold, and range of motion of the neck were assessed before and immediately after the treatment. RESULTS: Immediately after dry needling in the experimental group, the mean pain intensity was significantly reduced, but the mean pressure threshold and the mean range of motion of cervical spine were significantly increased. There were significantly larger changes in all three parameters of measurement in the dry-needling group than that in the control group. CONCLUSIONS: This study demonstrated the remote effectiveness of dry needling. Dry needling of a distal myofascial trigger point can provide a remote effect to reduce the irritability of a proximal myofascial trigger point.