J Oral Pathol Med (2012) 41: 689696 Background: The aim of this study was to investigate the roles of Matrix Metalloproteinases (MMP)-2, Metalloproteinases-7, Metalloproteinases-10 and Tissue Inhibitors of Metalloproteinase-1 (TIMP-1) in the pathogenesis of oral lichen planus (OLP) disease in same tissue samples. Methods: Thirty-nine individuals [29 patients with OLP (74%) and 10 healthy control subjects (25%)] were included in our study. The mean age was 48 +/- 14.39 with a range of 2075. Results: MMP-2 and MMP-7 expression was significantly different in the patient and control groups in the epithelium and the connective tissue (P < 0. 05). The ratio of MMP-2/TIMP-1 and MMP-7/TIMP-1 were higher in patient with OLP group than control group. Conclusions: Along with the exposure of the role of MMPs activity on diseases characterized by the tissue destruction, several studies were conducted on the pharmacological control of MMPs activity. However, understanding of the biological functions of MMPs is very important for the development and implementation of MMP inhibitors in the treatment of diseases. According to the results of this study, we suggest that MMP-2, MMP-7, and TIMP-1 may be involved in the formation of OLP lesions. Further studies on MMPs may be useful for understanding and treating the diseases such as OLP.