Abstract: Background: Diabetic retinopathy is a serious and common complication of long standing and poorly controlled diabetes mellitus that causes irreversible blindness. Raising awareness about diabetes mellitus and diabetic retinopathy is an important element for early diagnosis and controlling of this blinding disease. Purpose: To examine the effectiveness of an educational nursing intervention on knowledge and awareness of patients with diabetic retinopathy. Design: A quasi experimental design was used. It was conducted in outpatient clinic of Kafr El-Sheikh New Ophthalmology Hospital. Sample: A convenience sample of 140 patients with diabetic retinopathy was included. Instruments: I- An interviewing questionnaire was used that include socio-demographic data. II- Knowledge Assessment Questionnaire. Results: The present study revealed that the educational intervention for patients with diabetic retinopathy leaded to a highly significant improvement (p<0.0001) in the different categories of total knowledge about diabetes mellitus and diabetic retinopathy. The post intervention s' good knowledge responses increased from zero% pre-intervention to 94.3% for post intervention. Conclusion: Implementing of a designed nursing intervention has a significant role in improving knowledge and awareness among studied patients with diabetic retinopathy. Recommendations: The nursing roles should be directed toward improving knowledge and awareness of patients with diabetic retinopathy for good controlling of diabetic retinopathy and its subsequent complications