The clinical description (Espersen 1975) of a hypophysis-absces-syndrome in cattle is based on a retrospective analysis of 25 cases, which all were subjected to a patho-morphological examination after death or euthanasia. The post-mortem picture is characterized grossly by purulent, sero-fibrinous or serous inflammation of meninges, brain, cerebral ventricles, and pituitary region, with accumulation of pus in the pituitary region. The purlent inflammation in the pituitary region is often progressing intracranially but extradurally and involves adjacent cranial nerves, particularly the trigeminal and optic nerves. The extraneural viscera show chronic, embolic inflammatory processes in different organs in several cases as well as acute, agonal circulatory changes in the dead animals. A histological examination of selected parts of the brain and of the pituitary region from eleven of the cases shows in ten of these a protracted meningo-encephalitis and ventriculitis with gravitational extension to the basal meninges and the infundibulum of the hypophysis. The suppuration is further involving the pituitary cleft and adjacent parts of the pituitary (cf. fig. 1--6, 8--11). In one case only a large abces in teh adenohypophysis is found, without a concominant meningo-encephalitis (cf. fig. 7).