The development of new technologies within molecular biology and the mapping of the genome bring us closer to understanding the molecular basis of chronic inflammatory diseases, including the idiopathic inflammatory myopathies. This accomplishment appears particularly promising for the myopathies, because the muscle is an organ that is easily available for tissue studies and is thus particularly suitable for studies of molecular expression on both the gene and protein levels. The information gained from such studies will depend on the clinical characterization of the studied patients, which is another challenge concerning the inflammatory myopathies. In conjunction with the development of new technologies this area of clinical research is making progress through an international effort. As a result, new tools to assess disease activity and damage for inflammatory myopathies have been recently suggested. A combined effort to perform longitudinal studies on repeated muscle biopsies from patients who are well defined clinically, as well as genetically, is likely to bring us increased knowledge on disease mechanisms that could lead to the development of new therapies and an improved outcome for patients with chronic inflammatory myopathies.