• Purpose: To evaluate the efficacy and safety of twice-daily, preservative-free ketorolac 0.45% (Acuvail; Allergan, Inc, Irvine, California, USA) administration for treatment of inflammation and pain after cataract surgery. • Design: Prospective, randomized trial. • Methods: Two multicenter, double-masked studies randomized 511 cataract surgery patients (2:1) to receive twice-daily ketorolac 0.45% or vehicle in the operative eye for 16 days, beginning 1 day before surgery. The primary efficacy end point was the percentage of patients with a summed ocular inflammation score of 0 for anterior chamber cell and flare on postoperative day 14. The main secondary efficacy end point was the percentage of patients with no pain on postoperative day 1. • Results: On day 14, 52.5% of ketorolac patients and 26.5% of vehicle patients had an summed ocular inflammation score of 0 (P < .001). On day 1, 72.4% of ketorolac patients and 39.7% of vehicle patients had a pain score of 0 (P < .001). Median time to pain resolution was 1 day in the ketorolac group and 2 days in the vehicle group (P < .001). The percentage of ketorolac and vehicle patients who had a +3-line or more improvement in best-corrected visual acuity from baseline was 60.5% versus 44.0% on day 14 (P = .002). Overall, adverse events were more prevalent in the vehicle group than in the ketorolac group (48.5% vs 35.2%; P = .004). Burning or stinging (per a composite Medical Dictionary for Regulatory Activities) was reported by 1.5% of ketorolac patients and 0.6% of vehicle patients. • Conclusions: Twice-daily ketorolac 0.45% was well tolerated and effectively treated inflammation and pain following cataract surgery.