Erythroplakia is a pre-malignant condition of the oral mucosa (similar to erythroplasia of Queyrat) that typically appears as a demarcated red patch that clinically cannot be diagnosed as any other condition. One study suggested that greater than 90% of such lesions are dysplastic, carcinoma in situ, or invasive carcinoma at the time of diagnosis.

Erythroplakia tends to occur in older individuals. The lesions may be painless, tender, or painful. In some instances, the lesions are not just red but admixed with white areas, and these have been termed "erythroleukoplakia" or "speckled leukoplakia." Patients often have a history of cigarette smoking. The lesions are often painless, so the patient may not be aware of how long they have been present. If not treated, the lesions will continue to grow over months and years and eventually develop invasive carcinoma.