Inflammatory myopathies are an heterogenous group of diseases that include dermatomyositis (DM), polymyositis (PM) or inclusion body myositis (IBM). Their main features are acquired muscle weakness, inflammation and abnormal expression of MHC-I in the muscle fibers. The etiology is unknown but their pathogenesis is considered to be immunemediated. We performed microarray experiments, in microdissected MHC-I positive muscle fibers, avoiding inflammatory infiltrates, of a series of well characterized patients with DM, PM, IBM and in MHC-I negative muscle fibers from healthy controls. Analysis of the data revealed a distinctive pattern of abnormally expressed molecules related to innate immunity pathways specifically in DM. Innate immunity is important in the recognition of viral infections and danger signals and its dysregulation is related to autoimmunity. Previous studies in DM have shown evidence of altered expression of toll-like receptors and their contribution to IFN-beta upregulation. The microarray results are being confirmed by protein expression in muscle samples from DM,PM and IBM using immunohistochemistry. Our results confirm previous studies and interestingly, add new novel innate immunity pathways that could explain specific immunopathogenic mechanisms in DM. In addition, these mechanisms may be responsible of perpetuating the immune response after an initial infectious trigger. This knowledge will contribute towards the discovery of new biomarkers and improve the therapeutic management by making it more disease specific.