Oral ulceration is a common problem, and is sometimes a marker of gastroenterological disease. Patients with signs or symptoms of oral ulcers are sometimes referred to gastroenterology clinics, however, in most instances the ulcers does not reflect gastrointestinal disease. Indeed, a spectrum of disorders other than those of the gut can give rise to oral mucosal ulcers ranging from minor local trauma to significant local disease such as malignancy or systemic illness. This present article reviews aspects of the aetiology, diagnosis and management of common ulcerative disorders of the oral mucosa.