This was a multicenter, double-blind (DB), placebo-controlled, randomized discontinuation trial to evaluate the efficacy of pregabalin monotherapy for durability of effect on fibromyalgia (FM) pain. The trial included a 6-week open-label (OL) pregabalin-treatment period followed by 26-week DB treatment with placebo or pregabalin. Adults with FM and ≥40-mm score on 100-mm pain visual analog scale (VAS) were eligible. During OL weeks 1–3, patients received escalating dosages of pregabalin to determine their optimal dosages. During OL weeks 4–6, patients received their optimal fixed dosages (300, 450, 600 mg/d). To be randomized, patients must have had ≥50% decrease in pain VAS and a self-rating of “much” or “very much” improved on Patient Global Impression of Change (PGIC) at the end of OL. Double-blind treatment was with placebo or the patient’s optimal fixed dosage of pregabalin. Primary outcome was time to loss of therapeutic response (LTR), defined as <30% reduction in pain (from OL baseline) or worsening of FM. A total of 1051 patients entered OL; 287 were randomized to placebo, 279 to pregabalin. Time to LTR was longer for pregabalin versus placebo (P < .0001). Kaplan–Meier estimates of time-to-event showed half the placebo group had LTR by Day 19; half the pregabalin group still had not lost response by trial end. At the end of DB, 174 (61%) placebo patients met LTR criteria versus 90 (32%) pregabalin patients. Pregabalin was well tolerated, though 178 (17%) discontinued during OL for treatment-related adverse events (AE), and more pregabalin than placebo patients discontinued for AEs during DB. In those who respond, pregabalin demonstrated durability of effect for relieving FM pain.