Background The benefit of laser treatment in patients with branch retinal vein occlusion (BRVO) is established in the literature. We investigated the relationship of morphological and fluorescein angiographic findings with the results of laser treatment. Patients and methods Of 211 examined patients with BRVO argon-laser coagulation was performed in 121 (57%). Laser treatment was done in all patients with preretinal neovascularization and in patients with macular edema 3 months or more after the onset of occlusion with visual acuity less-than-or-equal-to 20/40. Follow up examinations were performed in 3 months intervals with the last examination 11,7 months on average after treatment. Statistical analysis was done by Wilcoxon-test. Results Mean visual acuity before laser coagulation was 20/60, after laser treatment 20/50. Visual acuity in all patients improved significantly after laser treatment (p=0,0001). A significant improvement occured when treatment was performed within 3 to 4 months after onset (p<0.0001), in patients with macular edema in the ischemic (p = 0,0005) and non ischemic type (p = 0,036), in patients without preretinal neovascularization (p < 0,0001) and without vitreous hemorrhage (p = 0,0001), in patients between 51 and 60 years (p = 0,0001) and between 41 and 50 years of age (p = 0,0086), in vein occlusions with intraretinal hemorrhages + + (p = 0,0001), with hard exsudates + (p = 0,0047) in vein occlusions of the temporal superior (p=0,0016) and the temporal inferior branch (p = 0,028) and in patients with diffuse dye leakage + (p = 0,0036) and + + (p = 0,007). No significant visual improvement was found in patients with ischemic maculopathy, hard exsudates + +, preretinal neovascularization and vitreous hemorrhage, diffuse intraretinal dye leakage + + +, dye leakage + + and . . . from retinal vessels and in patients less-than-or-equal-to 40 and > 60 years of age. Conclusions Laser treatment in BRVO according to the criteria of the study is beneficial and results in significant visual improvement.