Clinical and epidemiological observations suggested that a complex toxic molecule is involved in the parrotfish flesh (Scarus gibbus) poisoning from Gambier Islands. The fat soluble extract obtained from the muscles upon ciguatoxin preparation showed two toxic substances after fractionation by DEAE cellulose column chromatography. The major toxin is different from ciguatoxin judging by its chromatographic behaviour. The other is closely similar to (or identical with) ciguatoxin from the moray eel Gymnothorax javanicus. They were named SG1 for the new toxin and SG2 for the ciguatoxin like compound. Successive filtrations on Sephadex LH-20 of SG1 and SG2 gave respectively a lethality to mice of 0.03 microgram/g and 0.06 microgram/g. SG1, specifically occurs in the muscles of the parrotfish family (scaritoxin) while it is absent from other ciguateric fishes. According to that specificity and the lack of SG1 in S. gibbus liver and gut contents, the origin of scaritoxin is briefly discussed.