BACKGROUND AND OBJECTIVE: To determine whether postoperative use of topical ketorolac tromethamine 0.5% affects intraocular pressure (IOP) following Ahmed glaucoma drainage device (New World Medical, Inc., Rancho Cucamonga, CA) implantation. PATIENTS AND METHODS: Patients undergoing Ahmed implantation at the University of Michigan from January 2002 to June 2008 were reviewed. Fourteen eyes received ketorolac after surgery; 50 eyes did not. Preoperative and postoperative IOP and glaucoma medications were recorded for both groups; the two-sided Student's t test was used to compare these parameters. RESULTS: Mean preoperative IOP was similar in the two groups (35.1 ± 11.9 vs 37.0 ± 12.2 mm Hg; P = .60). At postoperative month 6, the ketorolac group had significantly lower IOP compared with the no ketorolac group (13.1 ± 3.7 vs 19.5 ± 9.3 mm Hg, respectively; P = .0003). There was no difference in the number of glaucoma medications postoperatively between the two groups. CONCLUSION: Ketorolac may lead to lower postoperative IOP following Ahmed implantation.