Purpose: To compare outcomes of vitreous lavage with and without intraoperative fluorescein angiography (FA) in eyes with delayed postoperative vitreous cavity hemorrhage. Methods: This prospective case-control study included patients with postoperative vitreous cavity hemorrhage who were randomized into 2 groups (intraoperative FA and lavage-only groups). Findings such as areas of untreated capillary nonperfusion, active neovascularization, and diffuse peripheral leakage in the retinal periphery were noted in the intraoperative FA group. Appropriate steps were performed, including additional endolaser and/or cryotherapy. In the lavage-only group, these steps were based on the surgeon’s discretion. Results: Twenty eyes of 19 patients were included in each group. All eyes showed unlasered areas of capillary nonperfusion on intraoperative FA, and targeted photocoagulation was performed. Six eyes showed diffuse peripheral leakage near the ora serrata in addition to areas of capillary nonperfusion, for which cryotherapy was performed. At 6 months, none of the patients in the intraoperative FA group had a recurrence of postoperative vitreous cavity hemorrhage, whereas 3 eyes in the lavage-only group developed recurrence. This difference was not statistically significant (P = .92). There was no significant difference in the best-corrected visual acuity between the groups at 6 months. Conclusions: There were no instances of recurrent hemorrhage in the intraoperative FA group. Preliminary data suggest the potential role of this technique to determine the causes of postoperative vitreous cavity hemorrhage as well as to reduce the rate of recurrence.