Immunopathogenesis of Campylobacter jejuni-associated Guillain-Barré syndrome (GBS) is not yet well established probably due to lack of experimental model. Therefore, we studied the Th1/Th2 immune response and pathological changes in C. jejuni-induced chicken model for GBS. C. jejuni (5 × 10(9) CFU/ml) and placebo were fed to 30 chickens each. Stools of all birds were negative for C. jejuni by culture and PCR before experiment. The birds were regularly assessed for disease symptoms up to 30 days. Sciatic nerves from all chickens were examined at 5 days intervals by histopathology and immunohistochemistry, and also for the expression of Th1/Th2 cytokines. Twenty-two chickens (73.3%) developed diarrhea after C. jejuni infection; 18 (60.0%) experimental chickens developed GBS-like paralytic neuropathy. Pathology in the sciatic nerves of these chickens included perinodal and/or patchy demyelination, perivascular focal lymphocytic infiltration, myelin swelling and presence of macrophages within the nerve fibers on 10th-20th post-infection day (PID). Cytokines (IFN-γ, IL-1β, TNF-α, IL-6 and IL-2) were elevated in early phase (5th-15th PID) and TGF-β2, IL-10 and IL-4 in the recovery phase (25th-30th PID) of the disease. The study provides evidence that C. jejuni infection in the chicken can provide an experimental animal model of GBS.