Crohn's disease is an inflammatory bowel disease which affects whole gastrointestinal tract from mouth to anus. Crohn's disease may present both oral manifestation and gastrointestinal symptom-abdominal pain, diarrhea, weight loss, anorexia, fever, and growth failure. The prevalence rate of oral manifestation is approximately between 0.5% and 20%. The oral lesion could be the first sign of Crohn's disease. We present a case of Crohn's disease in a patient who did not show typical oral manifestations but had nonspecific aphthous like ulceration and burning sensation for many years. Through this case, we suggest approaches for the diagnosis and treatment of the oral lesion of Crohn's disease.