Purpose To share the experience of using ultra-widefield fluorescein angiography (UWF-FA) in recognizing the potential signs for retinal neovascularizations (NVE) development in branch retinal vein occlusions (BRVO). Methods Reporting angiographic findings in 60 BRVO eyes presenting with NVE and vitreous hemorrhage using UWF-FA investigation. Angiographic retinal ischemic index (ARI) was also calculated from UWF-FA as the ratio of digitally mapped ischemic retina area against area of optic disc, termed unit of disc diameter (DD). Results We observed emerging angiographic features common to these patients: pattern of a localized non-perfused retina at early phase of UWF-FA remaining non-perfused at the late phase (black retinal ischemia, black-RI) (100%); presence of retinal microvascular anomalies (RMAs) at the “water-shed-border” of black-RI (100%); site of NVEs observed at either the same “water-shed-border” (42%) or from the main vessel branch within the black-RI (30%), or from both sites (28%); multiple NVEs were observed in all eyes except two with single active NVE. Median ARI size was 114 DD (SD 80 DD), range 5–354 DD. Conclusion We report a recurring angiographic pattern common to eyes with active BRVO-NVEs from UWF-FA, and NVEs in this clinical group can develop from varied ARI sizes. Further studies would be needed to establish the role of UWF-FA in predicting angiographic risk factors for BRVO-NVE.