Objectives This study was designed to evaluate the safety and efficacy of a single large dose (0.7 mg) of ranibizumab for treatment of macular edema secondary to nonischemic central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO). Setting and design A prospective interventional case series study was conducted at Tiba Hospital for Eye Surgery (private practice) in collaboration with the Ophthalmology Department, Assiut University, Egypt, from March 2013 till March 2014. Patients and methods A total of 10 eyes of patients having macular edema caused by nonischemic CRVO or BRVO were treated by intravitreal injection of a single large dose (0.7 mg) of ranibizumab. Fluorescein angiography and spectral-domain optical coherence tomography were done for every patient before treatment, and follow-up was done with spectral-domain optical coherence tomography after injection of ranibizumab at 1, 3, and 6 months. Results There was significant resolution of macular edema after intravitreal injection of a single large dose (0.7 mg) of ranibizumab (macular thickness was 535.5±214.7 µm at baseline compared with 281.3±145 μm at 6 months on follow-up; P=0.045) There was also significant improvement in best-corrected visual acuity (0.15±0.07 at baseline compared with 0.71±0.3 at 6 months on follow-up; P=0.007). There were no ocular or systemic adverse events documented during the 6-month follow-up period. Conclusion A single intravitreal injection of large dose (0.7 mg) of ranibizumab is a new promising regimen for managing macular edema secondary to nonischemic CRVO or BRVO.