We reviewed the clinical findings, color photographs, and fluorescein angiograms of 147 patients (154 involved eyes) who participated in the Branch Vein Occlusion Study through the Bascom Palmer Eye Institute for the presence of macroaneurysms within or adjacent to the zone of branch vein occlusion. Four distinct categories of macroaneurysms included arterial, venous, capillary, and collateral-associated types. We identified 59 lesions among 25 of the 154 (16.2%) affected eyes. Intraretinal lipid exudation and hemorrhage were commonly observed around the lesions, but these complications usually did not affect visual acuity. Macroaneurysms were associated with capillary nonperfusion on fluorescein angiography. Retinal neovascularization occurred in eight of 25 eyes (32%) with macroaneurysms.