Peroxisome proliferator-activated receptor gamma (PPARgamma) agonist such as thiazolidinedione (TZD) has important roles in inflammation and cancer in addition to the control of energy conservation, adipocyte differentiation and insulin sensitivity. PPARgamma is a ligand-activated nuclear receptor. In the absence of ligand, the transcriptional activity of PPARgamma is suppressed through the association with N-CoR/SMRT and histone deacetylases. Upon binding of ligand to PPARgamma, PPARgamma binds several coactivators and regulates the expression of its target genes in various tissues. To understand various effects of TZD, we summarize the transcriptional control by PPARgamma focused on coactivators and target genes regulated by PPARgamma.