Poisoning cases caused by drugs and toxic substances in forensic chemistry reported by National Research Institute of Police Science (Japan) from 1983-1997 were presented. These drugs and chemicals were used for homicide, suicide, misuse or accidents. Poisoning was classified into the following categories : carbon monoxide, volatile substances, drugs, pesticides and others. These categories were further subdivided as to specific drugs or chemicals involved. Carbon monoxide is the leading agent accounted for two thirds of poisoning cases. Over a fifteen years period the number of poisoning cases by volatile and other chemicals remained steady. The number of pesticide poisoning declined, especially that of paraquat and diquat formulations remarkably decreased to 200-300, while poisoning cases of phosphorus containing amino acid-type herbicides (glyphosate, glufosinate and bialaphos) have been increasing year by year. Drug induced poisoning using bromvalerylurea, barbiturates, benzodiazepines, and tricyclic antidepresants increased. A significant number of poisoning were placed in multiple drugs or pesticides, and mixed drug categories.
