Peroxisome proliferator-activated receptor gamma (PPARgamma), one of the nuclear receptors, is expressed at high levels in adipose tissue and is related to adipocyte differentiation and insulin sensitivity. PPARgamma is also expressed at high levels in digestive organs, especially in the colon epithelium. The physiological and pathological roles of PPARgamma in the gastrointestinal tract have been investigated and recognized as an endogenous regulator of innate immunity, inflammation, and cell proliferation. PPARgamma ligands have recently been reported to improve the condition of patients with non-alcoholic steatohepatitis (NASH). Thus, PPARgamma ligands are indeed potential benefit candidates for various digestive diseases. In this review, we will focus on the current knowledge and new insights of the roles of PPARgamma in digestive diseases, especially in (1) inflammatory bowel disease (IBD), (2) colon cancer, and (3) NASH.