Education is an important aspect of care for diabetic patients. This study aimed to compare the effect of education by health care provider and peer on self-care behaviors among Iranian patients with diabetes. In this clinical randomized control trial, we enrolled 120 patients with type 2 diabetes who were referred to the Diabetes Clinic at a university medical center hospital in an urban area of Iran. Participants were randomly allocated into three groups. Patients in care provider group (CPG) received additional education provided by a nurse, other than routine education in a Diabetes Clinic. Patients in peer education group (PEG) received education given by a peer. Patients in control group (CG) received the routine education in accordance with the usual procedures at the Diabetes Clinic. Data collected at baseline and 12 weeks (3 months) were demographic variables and diabetes self-care activities. Self-care behaviors post intervention differed significantly by group; PEG patients demonstrated the greatest improvement. CG patients' self-care behaviors did not change significantly and were significantly lower than scores by CPG and PEG patients. In line with the World Health Organization recommendations, future studies are warranted to confirm the effectiveness of peer-led education among diabetic patients in the Iranian culture.