Matrix metalloproteinases (MMPs) are proteolytic enzymes believed to be involved in many physiological and pathological processes associated with inflammatory reactions. MMP synthesis and functions are regulated by three major mechanisms including transcriptional activation, post-transcriptional processing, and control of activity by tissue inhibitors of metalloproteinases (TIMPs). Many cell types have been identified as producers of MMPs and TIMPs in a context of inflammatory processes. MMPs are involved in numerous inflammatory diseases, including respiratory, cardiovascular and central nervous system pathologies. This volume presents new advances in the involvement of MMPs in various diseases associated with inflammatory processes. Moreover, the recent development of selective and non selective inhibitors of MMPs provides new insights in the relationship between activation of inflammatory cells and tissue remodelling and advises new therapeutic possibilities for the treatment of inflammatory diseases.