Abstract: Objective　To investigate the diagnosis and treatment of Crohn disease in neonates. Methods　 The clinical data of one case of neonatal onset Crohn disease were retrospectively analyzed. Results　 Male infant had intermittent fever, recurrent oral ulcers, skin impetigo and intermittent diarrhea with increased WBC counts from five days after birth. He had been diagnosed as sepsis, bacterial enteritis, Behcet's disease, immunodeficiency disease, nutritional anemia, milk intolerance, and inflammatory bowel disease. Finally he was diagnosed as Crohn disease by rectal mucosa pathology and postoperative bowel pathology. He died of intestinal perforation on 8 months. Conclusions 　The infants who have recurrent oral ulcers, skin impetigo, perianal ulcers and fever from neonatal should undergo colonoscopy for the diagnosis.