To evaluate the efficacy and safety of XG-102 (brimapitide) compared to dexamethasone eye drops in the treatment of postoperative ocular inflammation. Multicenter, randomized, parallel group, double-masked, noninferiority clinical trial. Patients who underwent anterior and posterior segments combined surgery or glaucoma surgery or complex posterior segment surgery were eligible to participate. Patients were administered a single subconjunctival injection of 250 μL XG-102 90 μg (n = 47) or 900 μg (n = 48) or placebo (n = 50) at the end of ocular surgery. Subconjunctival injection for each group (XG-102 90 μg, XG-102 900 μg, or placebo) was followed by eye drops instilled 4 times per day for 21 days with placebo, placebo, or dexamethasone solution, respectively. The primary outcome measure was anterior chamber cell grades at day 28 comparing XG-102 900 μg with dexamethasone. The anterior cell grades for both XG-102 groups were noninferior to dexamethasone (−0.054 anterior cell grade 95% confidence interval −0.350–0.242; P < .001 for noninferiority) for XG-102 900 μg and −0.086 anterior cell grade (95% confidence interval −0.214–0.385; P = .003 for noninferiority) for XG-102 90 μg. Rescue medication was introduced for 10 (21%), 7 (15%), and 2 (4%) patients allocated to the XG-102 90 μg, XG-102 900 μg, and dexamethasone groups, respectively. The difference between XG-102 90 μg and dexamethasone was statistically significant (P = .013). The number of patients for whom adverse events were reported and the nature of the events reported was similar between the 3 treatment groups. A single subconjunctival injection of XG-102 at the end of ocular surgery is noninferior to dexamethasone eye drops in the treatment of postoperative ocular inflammation.