In medical literature peripheral neurological disorders are associated with Crohn's disease only in particular cases. We report on two patients who suffering from Crohn's disease developed an acute Guillain-Barré syndrome or a polyneuropathy associated with myositis. Two weeks after a 65-year old female patient developed a serious Guillain-Barré syndrome, a haemorrhagical Crohn's colitis was diagnosed. Within a few weeks the specific therapy led to a satisfying recovery. A 45-year old female had suffered from Crohn's disease since 12 years. Within 8 weeks she developed a serious sensorimotor mixed axonal and demyelinating neuropathy and a granulomatous myositis. After treatment with steroids her signs constantly decreased. These observations as well as a literature review show that polyneuropathy and Guillain-Barré syndrome can be associated with chronic inflammatory bowel diseases. Our results suggest that peripheral neurological signs could be regarded as a possible extraintestinal manifestation of inflammatory bowel disease.