Abdominal aortic aneurysms (AAAs) constitute an important clinical problem as they occur in up to 8% of male patients over 60 years old. While the pathogenesis and epidemiology of classical AAAs are relatively well studied, patients with inflammatory aneurysms create a particularly interesting subset from the point of view of pathology and clinical presentation. Inflammatory abdominal aortic aneurysms (IAAAs) which represents 5% to 10% of AAAs, are characterized by firm, thick aortic wall with a shiny white appearance and perianeurysmal infiltration or fibrosis. Cellular immune mechanisms, as well as general pathological processes remain poorly defined. In a present report, we demonstrate isolation of cells from IAAA with subsequent detailed immunophenotyping of inflammatory infiltrate of the IAAA, in the context of clinical presentation and surgical repair. Inflammatory nature of aneurysm was related to radiological findings, while C-reactive protein CRP levels remained low. Aneurysmal wall was significantly infiltrated by leukocytes, which significantly differed from peripheral blood. In particular, T cell infiltration was strongly increased in IAAA, constituting 70% of infiltrating leukocytes. These were predominantly activated CD4+ lymphocytes that expressed early activation marker (CD69) (30% in IAAA vs. 1% in patients blood). T cells showed in turn high expression of CCR5 receptor for chemokine RANTES, which could in part explain high T cell recruitment. Here we describe a method for leukocyte isolation from IAAA and present a case of a patient in whom we confirm inflammatory nature of aneurysm, which has been suggested by infiltrate in computed tomography rather than typical inflammatory markers.