AbstractOral ulcers, although very common entity can be very challenging to diagnose because of their broad spectrum in etiology and presentation. Oral mucosal ulcers range from ulcers due to local trauma to infections, malignancy and other systemic illness. Oral ulcers are diagnosed based on the patient’s history, clinical appearance, site, duration and frequency and the underlying systemic condition. As the list of ulcerative lesions in the oral cavity is quite extensive, the focus here will be on the infective ulcerative lesions.