Ichthyoallyeinotoxism is a kind of Ichthysarcotoxism (fish flesh poisoning) responsible of an unusual clinical feature: it is the unique case of central nervous system Ichthyotoxicity. The most frequent signs are dizziness, loss of co-ordination and hallucinations. Digestive troubles and muscle weakness are uncommon. The responsible fishes are herbivorous or omnivorous species of the temperate or tropical seas: Siganidae, Kyphosidae, Mullidae, Mugillidae, and in the Mediterranean sea, the Saupe (Sarpa salpa, Sparidae). Only two cases have been collected by the Marseilles Poison Centre. The first one concerned a family who presented in a summer day of 1982 hallucinations (aggressive animals) a few hours after eating barbecued non-eviscerated saupes. The fishes were caught at l a Ciotat near Marseilles. Signs persisted around ten hours. In 1994, a second case was collected: a man, 40 years old and without previous history, was on holidays on the C ote d'Azur . He ate in a restaurant a baked saupe. He began to feel sick two hours after the meal, and in the morning, he presented severe hallucinations. At the hospital, investigations did not find any aetiology of such signs (carbon monoxide or benzodiazepine intoxication). The signs lasted 20 hours, and he recovered with a total amnesia of the facts. As ichthyoallyeinotoxism is uncommon, a psychiatric misinterpretation, with psychosis diagnosis, can be done. The real cause of this poisoning is unidentified, but several authors think that it could be macroalgaes toxins accumulated in the fish flesh--for example toxins of Caulerpa prolifera in the Mediterranean Sea (1).