Background: there were over 7.8 million cases of diabetes in Egypt in 2015. The prevalence of diabetic retinopathy in Egypt among adult diabetic patients in 2010 was around 20.5%. 90 percent of all cases of blindness from diabetes can be prevented.  Copeptin, a novel biomarker (a surrogate to arginine vasopressin was found to increase with diabetic nephropathy. Objectives: this study aimed to detect the level of copeptin in patients with diabetic retinopathy.Patients and Methods:  the study was conducted on individuals attending the diabetes and the ophthalmology outpatient clinics in Ain Shams University Hospitals between February and August 2017.  This study included 96 individuals and they were divided into 4 groups. Group I consisted of 24 patients with proliferative diabetic retinopaty (PDR), group II 24 patients with non proliferative diabetic retinopathy (NPDR), group III included 24 diabetic patients with no fundus abnormalities and group IV included 24 healthy non diabetic individuals. The individuals were subjected to full medical history taking, slit lamp biomicroscope fundus examination and the measurement of serum fasting blood sugar, 2 hour post prandial blood sugar, glycated hemoglobin, serum creatinine, serum copeptin and urinary albumin creatinine ratio. History taking included age, gender, type of diabetes, duration of diabetes, antidiabetic medications, any other medical comorbidities and pregnancy for females. Results: the present study showed a statistically significant rise in the level of copeptin in patients with PDR (Group I) and NPDR (Group II) when compared to those with no diabetic retinopathy (Group III) and the control group (Group IV) (P value <0.001). There was a statistically significant positive correlation with duration of diabetes (r = 0.589) and level of albumin/creatinine ratio (ACR) (r = 0.540) (P value <0.001) for both parameters. Conclusion: level of copeptin was found to be higher in patients with diabetic retinopathy, in patients with longer duration of diabetes and in those with elevated ACR. It was higher in diabetics in comparison to normal individuals.