There was 1 victim of neurotoxic food poisoning from an adulterated dried mullet roe in Kaohsiung, Taiwan, in March 2001. The victim exhibited typical neurotoxic symptoms. The residue of dried mullet roe retained by the victim was assayed for toxicity and mitochondrial DNA. Its toxicity was 3450 mouse units per gram. The toxin was partially purified and identified as tetrodotoxin and derivative. The sequence of the 376-nucleotide region in the cytochrome b gene of the mitochondrial DNA exhibited the same genotype and the same restriction site for SapI as that of the toxic puffer fish Lagocephalus lunaris.