An array of investigations has revealed that macrophage migration inhibitory factor (MIF) plays an important role in the exacerbation of a wide range of inflammatory diseases. For the past two decades, we have extensively studied MIF's pathophysiological roles in human diseases, and have accumulated evidence elucidating its molecular mechanisms in the pathogenesis of immune disorders and inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel diseases (IBD). In a study of IBD, we demonstrated for the first time that anti-MIF antibody suppressed the degree of dextran-sulfate sodium (DSS)-induced colitis, indicating its potential therapeutic use for IBD patients. Following that report, a number of researchers, including us, clarified that MIF was profoundly involved in various gastrointestinal disorders, such as hepatitis and pancreatitis. We recently revealed that a MIF-deficient mouse was resistant to a challenge of DSS, and showed few clinical and pathological signs. Currently, we are developing new therapeutic approaches targeting MIF in inflammatory disorders, particularly IBD. We here overview MIF's pathophysiological function, mainly in IBD, and introduce two therapeutic approaches, anti-MIF antibody treatment and MIF-antisense therapy, via a drug delivery system using 1,3-beta glucan.