Type 2 diabetes mellitus (T2DM) is an insulin-resistant state characterized by an increased low-level inflammation and oxidative stress which are probably the initiation of diabetes-related cardiovascular complications. The aim of the study was to evaluate the impact of Mediterranean-style diet on inflammation and atherosclerosis markers in T2DM patients. Twenty-five overweight/obese T2DM patients (age 54.1±1.9 years, diabetes duration 7.8±1.3 years, HbA1c≥7.0%) were following (within 3 months) isocaloric dietary recommendation on food intake, i.e. rich in olive oil, fish, vegetables and fruits. Insulin resistance (IR) was calculated using Homeostasis Model Assessment (HOMA). The two-tailed t-test was applied for statistical analysis. In T2DM patients, starting values of adiponectin, HDL-cholesterol, paraoxonase activity (PON) and erythrocyte reduced glutathione (GSH) were significantly (P<0.050.001) decreased whereas levels of sICAM, C-reactive protein (CRP), ferritin and insulin were significantly enhanced (P<0.050.001) compared to healthy subjects. Adiponectin was increased after dietary intervention (P=0.018) whereas tumor necrosis factor alpha (TNF-α) and sICAM were decreased (P=0.004, P=0.007, respectively), serum ferritin was also diminished (P=0.028). There were no significant differences in CRP, HbA1c, HOMA-IR before and after the diet. But HDL-cholesterol, PON and GSH levels were enhanced after diet therapy (P=0.001, P=0.03, P=0.004, respectively). Thus, consumption of the Mediterranean-style diet within 3 months by T2DM patients induced geterogenous anti-inflammatory and anti-atherogenic effects against the background of stable glycaemic state. These finding may implicate a potential use of Mediterranean-style diet as effective non-pharmacological mean for aggressive intervention against diabetes-associated cardiovascular risk factors.