Inflammatory bowel diseases (IBD), Crohn's disease (CD) and ulcerative colitis (UC), were retrospectively assessed on the incidence and prevalence in Vukovarsko-Srijemska County, continental Croatia. There were a total number of 150 patients, 119 with UC and 31 with CD. Of them, 79.3% were patients with UC, indicating a predominant participation of UC in the sample. Comparisons between the period of surveillance, 2001-2010, and the decade before, 1991-2000, showed a significant increase in the incidence rates of both, UC and CD (UC 3.5, CD 0.95, 2001-2010, and UC 1.0, CD 0.45, 1991-2000). Comparison of this study with that performed in Primorsko-Goranska County, coastal Croatia, revealed different distribution patterns of IBD. In Primorsko-Goranska County, significantly higher incidence and prevalence rates of UC and CD and rather equal ratios between two diseases, were observed. The results are indicative of the differences between more developed Western and less developed Eastern parts of Croatia.