The peroxisome proliferator activated receptor gamma is a member of the nuclear receptor superfamily of ligand-dependent transcription factors and is the molecular target of antidiabetic thiazolidinediones that exert insulin sensitizing effects in adipose tissue, skeletal muscle and the liver. In addition to the well described effects of peroxisome proliferator activated receptor gamma in insulin target tissues, it is now apparent that its expression in macrophages is critical in the regulation of macrophage phenotype, whole body glucose metabolism and in mediating, in part, the antidiabetic actions of thiazolidinediones. As macrophages are major contributors to tissue inflammation and are resident in tissues responsible for maintaining glucose homeostasis, the therapeutic potential of these cells in the treatment of Type 2 diabetes is of significant clinical interest.