Oral lichenoid lesions (OLLs) are a diverse group of disorders that may be attributed to an autoimmune etiology, underlying systemic disease, or in association with an identifiable causative agent, such as a medication, food product, or dental material. OLLs commonly present with striae, erythema, and/or ulceration on affected oral mucosa and can be symptomatic. The aim of this report is to describe a case of OLLs that were believed to be attributed to use of household laundry detergent to clean an oral occlusal appliance. Keywords: laundry detergent, oral lichenoid lesion