Sixty-two patients with fibromyalgia were randomly assigned to receive 25 mg of amitriptyline at night, 500 mg of naproxen twice daily, both amitriptyline and naproxen, or placebo in a 6-week, double-blind trial. Amitriptyline was associated with significant improvement in all outcome parameters, including patient and physician global assessments, patient pain, sleep difficulties, fatigue on awakening, and tender point score. Patients taking the combined naproxen-amitriptyline regimen experienced minor, but not significant, improvement in pain when compared with patients who took amitriptyline alone. Amitriptyline, or amitriptyline and naproxen, is an effective therapeutic regimen for patients with fibromyalgia.