OBJECTIVE: To evaluate the efficacy of a novel variant of electroencephalograph biofeedback, the Low Energy Neurofeedback System (LENS), that utilizes minute pulses of electromagnetic stimulation to change brainwave activity for the amelioration of fibromyalgia (FM) symptoms. DESIGN: Randomized, double-blind, placebo-controlled clinical trial. SETTING: Tertiary referral academic medical center, outpatient. PATIENTS: Thirty-four patients diagnosed with FM according to 1990 American College of Rheumatology classification criteria. INTERVENTIONS: Active or sham LENS, depending on randomization, for 22 treatment sessions. OUTCOME MEASURES: Primary outcome measure was the Fibromyalgia Impact Questionnaire total score. Secondary outcome measures included number of tender points (TPs) and pressure required to elicit TPs on physical examination, quantitative sensory testing heat pain threshold, and self-reported cognitive dysfunction, fatigue, sleep problems, global psychological distress, and depression obtained at baseline, immediate post-treatment, and 3- and 6-month follow-up. RESULTS: Participants who received the active or sham interventions improved (Ps < 0.05) on the primary and a variety of secondary outcome measures, without statistically significant between group differences in evidence at post-treatment or 3- or 6-month follow-up. Individual session self-reported ratings of specific symptoms (cognitive dysfunction, fatigue, pain, and sleep, and overall activity level) over the course of the 22 intervention sessions indicated significant linear trends for improvement for the active intervention condition only (Ps < 0.05). CONCLUSION: LENS cannot be recommended as a single modality treatment for FM. However, further study is warranted to investigate the potential of LENS to interact synergistically with other pharmacologic and nonpharmacologic therapies for improving symptoms in FM.