In Crete, in southern Greece, a number of fatal carbamate poisonings were investigated over a period of 2 years, from 1991 to 1993. Five cases are reported, involving the fatal ingestion of methomyl (Lannate), a cholinesterase-inhibiting carbamate insecticide. Analysis of samples of blood plasma and serum showed more than 90% inhibition of cholinesterase. The blood methomyl concentrations had a mean value of 26.7 mg/l, and a range of 5.6-57.0 mg/l. These values are much higher than those previously reporter in similar cases (0.57-1.4 mg/l). Methomyl concentrations in organs and tissues were found to be significantly lower than those in blood and vitreous humour.