A pilot study to estimate the incidence of inflammatory bowel disease in Fiji is reported. Data from 1985 and 1986 for Indian migrants, Melanesians and other groups show the incidence of ulcerative colitis was 1.7/10(5)/year, in Indians, 0.15/10(5)/year in Melanesians and 1.4/10(5)/year in others. The minimum incidence of Crohn's disease is 0.14/10(5)/year. Indians are at significantly greater risk than Melanesians of developing ulcerative colitis.