Background: Diabetes is a complex and exhausting disease that needs the diabetic patients to pay attention regarding food, physical activity, and medication. Furthermore, it requires the patient to be knowledgeable and able to perform certain skills. Diabetic patients are exposed to long-term complications, including cardiovascular, neurological, renal and ophthalmic diseases. As well as, acute diabetic-related health conditions that can be life threatening and impact the diabetic patients' quality of life. Aim: The current study aims to examine the effectiveness of the Diabetic Health Education Program (DHEP) designed according to the guidelines of the International Diabetes Association in improving type 2 diabetes patient's knowledge and self-efficacy. Method: This study used a quasi-experimental design aimed at determining the effect of DHEP in improving knowledge and self-efficacy. The program utilized in this study was constructed by the researcher according to the International Diabetes Association guidelines. A sample of 130 diabetic patients was selected. Patients were randomly assigned into experimental and comparison groups, each group consisted of 65 patients. The experimental group attended the DHEP that was carried out in the diabetic clinic at Al-Hussein Medical City, Amman - Jordan, while the comparison group remained on the traditional care. The questionnaire utilized in this study was administered twice as a pretest and posttest for each group. Results: The study demonstrated the effectiveness of DHEP in improving diabetic patient's knowledge and self-efficacy. There were statistically significant improvements in patients' knowledge and self-efficacy between the two study groups. There were also statistically significant differences in knowledge and self-efficacy related to patient's training and higher level of formal education (p<0.05). However, the t-test showed that there were no significant differences in knowledge and self-efficacy due to gender and age (P > 0.05). Conclusions: DHEP has a positive effect on type 2 diabetes patients to improve their knowledge, self-efficacy, and clinical conditions such as blood glucose levels. Therefore, the generalization of such DHEPs is highly recommended. The findings of the current study present worthy data for the clinical nurses in recognizing diabetes patients self-efficacy, easing their experience in the clinical diabetes settings, as well as establishing an efficient diabetes educational program. This study could benefit future research. Key Words: Health education program, Jordan, Knowledge, Self-efficacy, Type 2 diabete