Oral lichen planus (OLP) is an idiopathic chronic inflammatory disease that affects the oral mucosa in approximately 2% of the Swedish population. Amalgam fillings may induce contact oral lichenoid lesions (cOLL) that can be difficult to clinically distinguish from OLP. It is not possible to histologically distinguish between OLP and cOLL. As their treatments differ, the correct diagnosis is vital. Toll-like receptors (TLR) are expressed by most of the body's cells and are part of the innate immune system, however they have also been linked to certain autoimmune diseases. OLP exhibits an increased amount of TLR in the epithelium. The purpose of this study is to investigate the variations in the expression of TLR4 and TLR9 in OLP and cOLL. Our hypothesis is that a histological difference in OLP and cOLL can be observed due to TLRs different roles in maintaining the immune response. Method: Tissue samples with histologically confirmed lichenoid reactions were chosen from Biobank, Oral Pathology, Malmö, from patients with the clinical diagnosis OLP (10 subjects) and cOLL (12 subjects). TLR4 and TLR9 were identified by immunohistochemical staining and compared between the two groups. Results: A significant difference was observed in TLR4 staining of fibroblasts, lymphocytes and macrophages where the antibody was less expressive in OLP. In TLR9 staining lymphocytes were stronger expressed in OLP compared to cOLL. Conclusion: Our results showed that there was a difference in the expression of TLR4 and TLR9 in cOLL and OLP, this could be a result of OLP being an autoimmune disorder. Further studies on this subject are recommended on this subject. MeSH: "Dental Amalgam", "Dermatitis, Allergic Contact", "Immunohistochemistry", "Lichen Planus, Oral", "Toll-Like Receptor 4", "Toll-Like Receptor 9"