Ten clinically intact weaned piglets were experimentally intoxicated by intravenous injection of lipoproteide-free lipopolysaccharide endotoxin according to Westphal of E. coli O 127:B8. Severe endotoxin shock with all clinical manifestations of experimental coli-enterotoxaemia was induced in all animals and included circulatory disorder with tachycardia, intermittent pallor and/or cyanosis, symptoms of severe systemic intoxication, neurological symptoms, such as lack of coordination, hindleg staggering, spasm, paresis, paralysis, changes in respiration, such as rise in respiratory frequency and deepened breathing premortal deceleration of respiration and gasping for breath, temperature, variation, including hyperthermia and aggravating hypothermia, gastro-intestinal symptoms, such as temporary vomiting and persistent diarrhoea, leucopenia, eosinopenia, variation of haematocrit, edematisation, increased transudation, congestion, and gastro-intestinal shock lesions. Eight animals died. These experiments quite obviously have confirmed that endotoxin shock is the common pathogenetic principle behind all forms of coli-entertoxaemia (i.e, the forms of edematisation, cardiovascular failure, and gastro-intestinal processes.) Lipopolysaccharide endotoxin alone may be responsible for the development of both edemas and neurotoxic symptoms (edema disease) and diarrhoea (gastro-intestinal form of coli-enterotoxaemia). The pathogenetic relevance of additional toxins (neurotoxin and enterotoxin) is discussed under this aspect.