The aim of this study was to determine the tissue colonization and pathogenicity of Arcobacter butzleri in BALB/c mice. For this purpose, 60 adult mice were distributed into three experimental groups consisting of 16 animals in each and into three control groups consisting of 4 animals in each. One ml of A. butzleri suspension containing 1x10(9) CFU/mL was inoculated by peroral (PO), intraperitoneal (IP) and intramammary (IMG) routes to BALB/c mice in experimental groups in order to determine the clinical and pathological findings. Animals in control groups received 1 mL of sterile saline solution. Duration of the experiment was limited for 15 days. The BALB/c mice were found to be susceptible to infection by the three ways of inoculation. In infected mice, diarrhea, weakness, decrease of body temperature (IP and IMG); hepatomegaly, splenomegaly (IP); swelling of mammary glands, exudation, abscess formation (IMG) were seen. Mortality was determined as 25% in PO inoculation group and as 95% in IP IMG inoculation groups. In histopathological examination, acute/chronic inflammation characterized with neutrophil and plasma cells and local necrosis or congestion (IP) were determined in the lungs, kidneys, regional lymph nodes, liver, spleen, stomach and colon. However, severe, diffuse and chronic pyogranulomatous and necrotizing inflammation and interstitial fibrosis were observed in mammary gland and its subcutaneous tissues (IMG). In all of inoculation groups, A. butzleri was reisolated until the 5th days of post inoculation. The results of this study have suggested that BALB/c mice might be an appropriate experimental animal model for studying A. butzleri infection.