OBJECTIVE: The incidence of ulcerative colitis ranges from 3 to 15 cases per 100,000 persons per year with a prevalence of 50–80 cases per 100,000, and the disease is 3–5 times more common among Jews. In Israel, Ashkenazi Jews have a higher incidence than Sephardi Jews, but a lower incidence than Ashkenazi Jews in the United States or Northern Europe. The aim of this study was to examine the prevalence, mean annual incidence, and clinical patterns of ulcerative colitis in a stable population of communal settlements (kibbutz). METHODS: We repeated a community-based survey in 124,400 kibbutz residents, 10 yr after our first study. This population represents 2.5% of the Jewish population of Israel. All ulcerative colitis patients were located by contacting the kibbutz clinics of the 269 kibbutz settlements (100% compliance). Data were updated to December 31st, 1997, which was designated the point prevalence date, and included information on gender, age, origin, education, profession, extent of the inflammatory process, clinical spectrum of the disease, therapy, complications of the disease, and treatment. The mean annual incidence for the 10 yr was calculated from the prevalence data. Only cases with a definite diagnosis of ulcerative colitis made in a recognized gastroenterology unit were accepted into the study. RESULTS: There were 208 confirmed cases of ulcerative colitis disease, 113 women and 95 men (female:male ratio = 1.19). The prevalence rate rose from 121.0/100,000 in 1987 to 167.2/100,000 in 1997 (p 16 yr and in women with 9–10 yr of education, 259.3 and 242.9/100,000, respectively. CONCLUSIONS: The prevalence of ulcerative colitis in this Israeli population increased and has reached the upper range for European and American populations. The mean annual incidence rate of ulcerative colitis is in the lower range of that reported for the Western countries.