We report a fatal case of suicide presenting with convulsions and subsequently multi-organ failure. Rodenticide poisoning was not suspected until the next day when tetramine was detected in the patient's blood, urine, and food residues. Tetramine is a potent rodenticide with a rapid action and high mortality. The poison has been banned worldwide but is still readily available in Mainland China. Outbreaks of poisoning are reported frequently and doctors should be alert for this lethal toxin.