Purpose: To assess the efficacy of intravitreal injection Ranibizumab on visual outcome and macular thickness in patients with Central retinal Vein Occlusion presenting with poor visual acuity. Place of study: Regional Institute of Ophthalmology, Guwahati Medical College & Hospital Type of study: Hospital Based Prospective Observational Study. Duration of study: 12 months Materials and Methodology: 45 eyes of 45 patients with CRVO were selected prospectively and recruited for intravitreal injection Ranibizumab at baseline and evaluated monthly till 6 months. The patients were given additional ranibizumab for macular edema when required on the basis of optical coherence tomography findings. Patients were evaluated for improvement in Visual acuity, Macular Thickness and complications. Results: There were 45 eyes of 45 naive CRVO patients who at baseline had a mean age of 57.81 years, a mean Visual acuity of 43.54(±18.26) in Early Treatment of Diabetic Retinopathy letters, and a mean central macular thickness of 546.09(±8.75)μm.At 6 months of follow up ,the mean visual acuity improved to 60.45(±18.96) letters and the central macular thickness decreased to 233.54(±8.75 ) μm (p<0.00001).Change in Visual acuity and macular thickness correlation was not evaluated . Conclusions: Use of Intravitreal Ranibizumab in cases of CRVO showed improvement in mean Visual Acuity, with low rates of adverse events in 6 months follow up period.