An adult female bowhead whale, Balaena mysticetus, from the Beaufort Sea, Alaska (USA), had necrosis of a well-demarcated portion of the mid-jejunum and adjacent mesentery, accompanied by fibrinous peritonitis. The veins within the mesentery adjacent to the affected intestine were severely dilated and hyperemic. There were no perforations of the gastrointestinal tract, nor any thromboses within the mesenteric veins. Death appeared due to the sequelae of intestinal volvulus and infarction; reduction of the displacement presumably occurred during handling of the animal.