The aim of this study is to investigate the Effect of Hazelnut Consumption on lipid profile, Apo B, Apo A-I, hs-CRP and Paraoxonase-1 in type 2 diabetic patients. In this parallel randomized controlled trial, 50 men and women with type 2 diabetes will be recruited from Institute of Endocrinology & Metabolism of Iran University of Medical Sciences. The subjects will be 35-70 y of age. Inclusion criteria are BMI≤35 kg/m2, TG<400 mg/dl, HbA1C<9%, LDL≤200 mg/dl and Blood pressure ≤ 160/90 mmHg . Exclusion criteria are known allergy to nuts, taking insulin, smoking cigarettes, following vegetarian or weigh-reducing diets. The study will be explained to each subject, who signs an informed consent. Prior to the study, the subjects will be required to complete 3-days 24-hour dietary recall. Diets will be analyzed for calorie and macronutrients content. Then, we will substitute 10% of usual daily calorie intake with hazelnut in intervention group. The control group will follow their habitual diet. Blood samples will be obtained after an overnight fast before and after the study. All anthropometric and physical activity variables will be measured both before and after the trial. Compliance will be assessed from 3-days 24-recalls which obtain at first, in the middle and at the end of the study. Diets and medications dosage will be held constant throughout the study and each subject’s exercise level will be kept constant and monitored by physical activity questionnaires (IPAQ).