Forensic toxicology deals with the investigation of toxic substances, poisonous products or with the environmental chemicals. This field of science helps to identify poison substance and hazardous chemicals. Forensic toxicology deals with the way that substances are absorbed, distributed or eliminated in the body – the metabolism of substances. This paper reviews the manifestations that each poisonous substance presents concentrating toward the commonly used poisonous substance especially in India. It also explains the Indian Penal Code, which is main criminal code intended to cover all substantive aspects of criminal law regarding poison.