The Guillain-Barre syndrome (GBS) could be a manifestation of neurotoxicity caused by multiple factors due to allogeneic bone marrow transplantations (alloBMT). In this paper we present a case of a 40-year old woman with chronic myeloid leukemia after alloBMT from her HLA identical brother. She developed the second grade of acute hepatic graft versus host disease (GvHD) shortly after alloBMT followed by chronic form. We observed Guillain-Barre syndrome probably triggering by GvHD in this patient.