Aim: To identify the most common cause and the frequent stage of presentation in patients with neovascular glaucoma. Materials and Methods: A prospective observational study was conducted in the Department of RIO, Indira Gandhi Institute of Medical Science, Patna, Bihar, India, for 1 year. Total 100 eyes of 90 patients having neovascular glaucoma in one eye or both the eyes were included in the study. All patients underwent thorough ocular examination i.e., visual acuity, slit lamp bio-microscopy, intraocular pressure (IOP) measurement by Goldman applanation tonometry, gonioscopy with Posner 4 mirror indirect gonioscope and dilated fundus examination. Results: The present study was conducted in 100 eyes of 90 patients out of which 80 patients had either eye involvement and 10 patients had both eyes involvement. All Patients were aged between 13-69 years with a mean of 54.63 ± 12.5 years. Out of 90 patients, 75 (83.33%) were males and 15 (16.67%) were females. The range of intraocular pressure (IOP) was 3-72 mm of Hg with mean of 29.52 ± 11.3 mm of Hg. On gonioscopic examination, most of the cases i.e., 54 (54%) had only rubeosis iridis without involvement of the angle, 19(19%), 12 (12%), 7 (7%), 6 (6%) had neovascularization of angle (NVA) in one; two, three and four quadrants respectively. 3 cases had hyphema. In the present study, most of the patients i.e., 54(54%) presented in rubeosis iridis stage, 31 (31%) in angle closure stage and 15 (15%) in open angle stage. Out of 100 eyes, 55 (65%) had diabetic retinopathy in variable severity, 12 (12%) had inflammatory etiology, 10 (10%) had retinal vein occlusion and 10 (10%) had glaucoma (PXG and absolute glaucoma. Conclusion: In the present study, it was found that Proliferative diabetic retinopathy is the most common cause and rubeosis iridis is the most common stage of presentation in NVG.