Sutton's ulcer is one of the recurrent oral ulcers. It normally occurs on the nonkeratinized oral mucosa and heals by scar formation. The cause is assumed to be an immunologic response to oral epithelium or the antigen of a microorganism. Therapy is unspecific or topcal use of antibiotics and cortisone is recommended. The exclusion of a local or systemic malignant desease seems to be the most important feature of a differential diagnosis.