The case of a man with poorly controlled ulcerative colitis, who developed a cytoplasmic antineutrophil cytoplasmic antibody-positive systemic vasculitis, causing small bowel infarction is reported. Antineutrophil cytoplasmic antibodies occur in 50-70% of patients with ulcerative colitis, but are usually of the perinuclear or atypical pattern; the cytoplasmic pattern seen in this case is indicative of systemic vasculitis. A variety of vasculitic diseases have been reported as occurring rarely with ulcerative colitis, but this report is the first description of a cytoplasmic antineutrophil cytoplasmic antibody-positive vasculitis with this association.