Background: the administration of anti-vascular endothelial growth factor (anti-VEGF) agents has become an application of IVIs to treat a variety of retinal and choroidal neovascular diseases including neovascular age-related macular degeneration, vein occlusion with macular edema, and diabetic maculopathy. ranibizumab is the most commonly used anti-VEGF treatments for retinal disease. While Intravitreal ranibizumab appears to be safe and effective but it can cause adverse effects as intraocular inflammation, cataract, vitreous haemorrhage, and increased intraocular pressure. Aim of the work: this study aimed to Evaluation of Iop changes after intravitreal injection of Ranibizumab retinal and choroidal neovascular diseases as neovascular age-related macular degeneration (AMD), central vein or branch vein occlusion with macular edema, and diabetic maculopathy Patients and Methods: this prospective study was carried out from March 2018 to September 2018 on 35 eyes of patients attending outpatient clinic of Al-Azhar University Hospitals and Ophthalmology Department of Research Institute of Ophthalmology in Giza. All participant names were hidden and were replaced by code numbers to maintain privacy of the patients. IOP was measured Using Applanation tonometer and Perkins tonometer before IVI of ranibizumab immediately after injection, 30 minutes, 1^ST day, 1^st week, and 1^st month after injection. Results: IOP was highly increased immediately after injection of ranibizumab, preoperative mean IOP 15.31±3.70, immediate after injection mean IOP 24.62±11.38, then it started to decrease till reaching normal values in the first 24h after injection, 1st 24hours mean IOP 16.31±3.60.The mean IOP for patients who were previously injected was 16.47±3.74 pre injection, and it was 30.88±12.55 immediately after injection, it still decreasing till reaching 20.24±2.77 after 30 minutes, we follow the patients after 1 day it was 18.41±3.12, then it became 18.29±3.62 after 1 week, and 17.88±3.33 after 1 month. The mean IOP for patients who were the first time to be injected was 14.22±3.41 pre injection, Immediate after injection the mean IOP was 18.72±5.92, after 30 minutes of injection the mean IOP was 15.44±3.99 mm Hg, after 1 day of injection the mean IOP was 14.33±2.87 mm Hg, We followed up the patients to one week after injection and we checked the IOP. The mean IOP after one week was 13.72±2.93mm Hg, We continue following the patients for one month and checked IOP, The mean IOP was 14.06±3.21 mm Hg. Conclusion: IOP tends to increase after intravitreal injection of Ranibizumab 0.05ml (0.5 mg). It causes mainly a transient immediate increase in intraocular pressure especially in patients who exposed to repeated intravitreal injection. This elevation of IOP tends to normalize after one day. Recommendations: this study recommend monitoring of IOP after intravitreal injection of ranibizumab and Care should be taken for cases with multiple injections and predisposing risk factors like glaucoma and glaucomatous patients