The prevalence of inflammatory bowel diseases (IBDs) is set to stabilize in Western Europe and North America, as opposed to its increasing trend in developing countries in Asia. The epidemiology of IBDs in areas where the incidence and prevalence are relatively low provides an opportunity for researchers to determine the unknown aspects of them. In this review article, the PubMed and MEDLINE databases were searched from 1970 to 2012 and the epidemiological aspects assessed in Iranian articles were compared with identical subjects in other Asian countries. During this period, there were 21 documented articles on IBD epidemiology in Iran and 52 in Asia. According to the present review, CTLA-gene polymorphism and male/female ratio in ulcerative colitis (UC), incidence of extra-intestinal manifestations, extent of intestinal involvement, and family history in both UC and Crohn’s disease (CD) seemed to be different between Asia and Iran. In contrast, the incidence of primary sclerosing cholangitis in IBD patients and association between NO2/CARD15 mutation and CD as C3435-T allele and UC were nearly the same. The rate of IBD has increased significantly in Iran, as has that of other Asian countries during the last decade. A thorough, well-designed...