Results of the retrospective, population-based study, 2000-2010, on inflammatory bowel disease, ulceratice colitis (UC) and Crohn's disease (CD), from Zadar County, have been presented and compared with world experience and comparative data from Primorsko-Goranska and Vukovarsko-Srijemska Counties. The average incidence rates (per 100 000) were 8.2 and 8.4, for UC and CD, respectively. Prevalence rates, at the end of the follow up, were 133.9 for UC and 111 for CD. Constant increase in the incidence rates for both, UC and CD, have been recorded, for CD more prominently in the second part of the follow up, 2006-2010. Prevalence rates have being continuosly rased for both diseases, data for UC exceeding that for CD. Results of data comparison among the counties contribute in favour to the hypothesis of Zadar County as a rapidly developing area and strongly argue against the existence of the North-South gradient between Vukovarsko-Srijemska and Zadar Counties.