Recent evidence demonstrates that the increased expression and activity of matrix metalloproteinases (MMPs) may contribute to intestinal tissue injury and inflammation in inflammatory bowel disease, and that MMP inhibition might be a new therapeutic approach to controlling inflammatory response. In addition, MMPs may play a crucial role in physiological and pathophysiological reactions such as leukocyte accumulation into inflamed tissue, cytokine production from inflammatory and epithelial cells, T lymphocyte homing to the intestine, wound healing and proliferation of epithelial cells, and intestinal innate immunity. This review focuses on recent progress in elucidating the biological and pathological roles of MMPs in inflammatory bowel disease.