Background: Diabetes mellitus is a group of metabolic disorders characterized by elevated blood sugar levels as a result of deficiencies in insulin secretion, insulin action, or both, which lead to abnormalities in glucose, lipid, and protein metabolism. Diabetic patients also have an increased risk of other diseases, including heart, peripheral, arterial, and cerebrovascular diseases. Aim: This study aimed to identify the relationship between knowledge and self-care practices among diabetic patients. Design: A correlational descriptive research design was used to accomplish the aim of the present study. Setting: The study was conducted at kafr Elziat General Hospital affiliated with the ministry of Health, in the outpatient clinic of diabetes. The outpatient clinic works six days a week from Saturday to Thursday from 9 Am-2 Pm. Subjects: A convenience sample of 150 adult patients was included in the study. Tool: One tool was used for conducting this study (Diabetic patient's knowledge and self-care practices structured interview schedule). Results: There were positive statistically significant differences between the patient's level of knowledge mean scores and the patient's age, level of education, and marital status where p = (0.008, 0.001, 0.031 respectively). There were positive statistically significant differences between patients' self-care practices mean scores and patients' age, sex, level of education, occupation, and marital status where p=(0.004, 0.001, 0.001, 0.004, 0.046 respectively). Conclusion: It can be concluded that more than half of the studied patients had a fair level of knowledge, in addition, more than half of the studied patients had a fair level of self-care practices. Recommendations: Development of health education programs for patients and their families to improve their knowledge about therapeutic regimens. A specialized survey should be done to explore barriers associated with diabetes management, including patient healthcare providers, and health systems-related barriers.