Histological examination of the surgical specimens of three patients presenting with intestinal ischemic necrosis disclosed extensive lesions of lymphocytic phlebitis associated with thrombosis of different ages. Arterioles and arteries were not affected. The lymphocytic infiltrate was composed of a mixture of T- and B-lymphocytes. None of the patients showed clinical or laboratory evidence of systemic vasculitis. Follow-up ranged between 4 months and 5 years. There has been no recurrence necessitating reoperation. The etiology of this clinicopathological entity has not been elucidated.