BACKGROUND: Fibromyalgia is a chronic widespread pain condition that is associated with sleep disturbances and cognitive impairments. Neurofeedback has been demonstrated to improve pain, sleep quality, and fatigue. However, few studies have examined the effect of neurofeedback for patients with fibromyalgia. AIM: To determine the effects of neurofeedback on pain intensity, symptom severity, sleep quality, and cognitive function in patients with fibromyalgia. DESIGN: This study was a randomized controlled trial. METHOD: Eighty participants were randomized to a neurofeedback group (N = 60), receiving sensorimotor and alpha rhythm feedback for 8 weeks, or a telephone support group (N = 20). RESULTS: Results from the generalized estimating equation modelling revealed significant group-by-time interactions for Brief Pain Inventory pain severity (B = -1.35, SE = 0.46, p = .003) and pain interference (B = -1.75, SE = 0.41, p < .001), Revised Fibromyalgia Impact Questionnaire total scores (B = -16.41, SE = 3.76, p < .001), sleep onset latency (B = -25.33, SE = 9.02, p = .005), and Psychomotor Vigilance Test error (B = -1.38, SE = 0.55, p = .013) after adjustments for age, sex, duration of illness, and group differences at baseline. CONCLUSIONS: An 8-week neurofeedback training regimen of sensorimotor rhythm and alpha brain waves significantly improved pain severity and interference, fibromyalgia symptom severity, sleep latency, and sustained attention in patients with fibromyalgia.