The gospel writer Luke and the Jewish historian Josephus give us only sketchy details of Herod Agrippa's death, but there is enough information to make a reasonable diagnosis. We are told that the disease process involved worms and was characterised by severe abdominal pain leading to death in five days. The large round worm Ascaris lumbricoides is the likely pathogen. Heavy infestation of the intestinal tract by this parasite commonly leads to small bowel obstruction, which may be complicated by volvulus, gangrene, perforation and peritonitis. The symptoms and time course of the Jewish king's fatal illness are consistent with this sequence of events.