Purpose: To report the intermediate-term results of the Baerveldt 250-mm2 Glaucoma Implant for treatment of adult glaucoma. Design: Retrospective, noncomparative, interventional case series. Participants: One hundred eight adult patients (108 eyes) with glaucoma who received a Baerveldt 250-mm2 Glaucoma Implant. Intervention: Implantation of the Baerveldt 250-mm2 Glaucoma Implant. Main Outcome Measures: Intraocular pressure (IOP), visual acuity, number of glaucoma medications, and surgical complications. Success was defined as IOP ≥ 6 mmHg and ≤ 21 mmHg (with or without antiglaucoma medications), without further glaucoma surgery, devastating complication, or loss of light perception attributable to drainage implantation. Results: Mean age was 63.8±16.5 years. Mean postoperative follow-up was 22.8 months (range, 0.2-84.9; interquartile range, 3.9-36.3). Mean preoperative IOP was 36.3±13.0 mmHg, on 2.9±1.1 antiglaucoma medications. The mean postoperative IOP at final visit was 15.8±7.6 mmHg (P<0.0001, paired t test), on 0.8±1.0 antiglaucoma medications (P<0.0001, Wilcoxon test). Kaplan-Meier success rates were 0.92 (6 months, n = 81), 0.88 (12 months, n = 75), 0.84 (18 months, n = 68), and 0.79 (24 months, n = 61). Conclusions: The Baerveldt 250-mm2 Glaucoma Implant provides good intermediate-term success for the treatment of adult refractory glaucoma.