Abdominal aortic aneurysm is a common condition with high mortality due to rupture; however, the condition also is associated with nonaneurysmal cardiovascular mortality. A possible contributing mechanism for the cardiovascular mortality is an imbalance between the proinflammatory and anti-inflammatory systemic response. In the present study, 78 patients with abdominal aortic aneurysm and 41 controls without aneurysm matched by age, gender and smoking habits were investigated. Cytokines such as interleukin-6, interleukin-10, and monocyte chemoattractant protein-1 were measured in plasma. There was significantly higher level of interleukin-6 in patients with AAA compared to controls. The interleukin-6/ interleukin-10 ratio was highest in patients with large compared to small abdominal aortic aneurysm. In conclusion, the present data indicate a proinflammatory response and a proinflammatory to antiinflammatory imbalance in patients with abdominal aortic aneurysm which is dependent by aneurysm size.