Over a 15-year period six patients (five female) of Afro-Caribbean origin presented with ulcerative colitis from a community of this ethnic extraction numbering 47,000 persons. The disease was characterised by an acute severe presentation, extensively affected bowel, an active course of disease and a propensity for severe hypersensitive reactions to oral sulphasalazine. These findings are of particular implication in the management of ulcerative colitis in West Indians.