OBJECTIVE: To determine the differences between clinical effects of electroacupuncture and biofeedback therapy in addition to conventional treatment in patients with cervical myofascial pain syndrome (MPS). DESIGN: Randomized clinical trial. SETTING: Physical medicine and rehabilitation clinic of a university hospital. PARTICIPANTS: Fifty patients (N=50) aged 25-55 years of both sexes with chronic neck pain diagnosed with MPS (characterized by trigger points within taut bands) were randomly assigned to 2 equal groups of 25 individuals. INTERVENTIONS: The patients in electroacupuncture group were treated with standard acupuncture and concomitant electrical stimulation; those in biofeedback group received visual electromyography biofeedback therapy for muscle activity and relaxation. Both groups received the intervention 2 times a week for a total of 6 sessions. Basic exercise training and medicines were administered for all the patients. MAIN OUTCOME MEASURES: Pain severity based on the visual analog scale (VAS), functional status using Neck Disability Index (NDI), cervical range of motion (ROM) using and inclinometer, and pressure pain threshold (PPT) using an algometer were evaluated before and at 3 and 12 weeks after the treatment. Primary outcome was defined as 20% reduction in the 3-month neck pain and dysfunction compared to baseline, assessed through the NDI. RESULTS: Fifty patients (39 women, 11 men) with a mean age (years) ± SD of 39.0±5.5 and neck pain duration (weeks) of 6.0±2.2 were analyzed. All parameters, except for PPT of the lower trapezius and paravertebral muscles were improved significantly in both groups, while baseline values were controlled. The primary outcome was achieved more significantly in the acupuncture group than in the biofeedback group: 20 (80.0%) vs 10 (40.0%); rate ratio=2 with 95% confidence interval (CI), 1.19-3.36; number needed to treat (NNT)=2.5 with 95% CI, 1.54-6.58. Advantages of acupuncture over biofeedback were observed according to values obtained from the NDI, VAS, extension and left lateral-bending ROM, and PPT on the left upper trapezius after the last session of intervention until 3 months (P<.05). CONCLUSIONS: Both electroacupuncture and biofeedback therapies were found to be effective in management of MPS when integrated with conventional treatment. However, intergroup differences showed priority of acupuncture in some parameters vs biofeedback. Thus, electroacupuncture seems to be a better complementary modality for treatment of MPS in the neck and upper back area.