Considering that poisoning phenomena, which is as old as the history of humanity, began to be recognized with observations that formed the basis for unnamed toxicological researches; the history of toxicology science is also quite old. The field has evolved through the collaboration of many disciplines, with contributions from chemistry, pharmacy, medicine, biology and engineering research, and has become indispensable in the service of justice by developing methods for the detection of natural, semi-synthetic and synthetic active substances. Forensic toxicological investigations, in addition to the elucidation of cases that have been brought to justice and resulted in death, direct both justice and scientific researches and treatment in many areas such as acute and chronic poisoning, illegal substance use / production, doping control, workplace substance use tests, consumer cases, elucidation of crimes against the environment, veterinary medicine, etc. This field, just like other disciplines, has its own technical and ethical rules; it is not possible for a forensic toxicologist to serve in the field without knowing and experiencing these rules. Toxicological research, an important component of forensic sciences, requires a strong laboratory infrastructure as well as researchers with the knowledge and experience to operate this infrastructure. It is the duration and quality of forensic toxicology education that is decisive for internalizing and applying the benefits of technology, conducting the laboratory processes of a forensic case in accordance with science and law, and reporting the results obtained accurately and reliably by evaluating them from an ethical and scientific perspective, as Arnold J. Lehman, the famous toxicologist of the field, said, "You too can become a toxicologist at the end of two easy courses, each lasting ten years". Since the number of experts trained in the field of forensic toxicology has been increasing with the spread of forensic sciences to large masses in recent years, there is a need for training programs and materials in which the relationship between the quality of education and the academic and technical infrastructure of the institutions providing education is well established. This book, which is intended to meet this need, is a reference book that addresses the issues that form the basis of forensic toxicology, deals with toxicology with its legal and analytical aspects, examines the drugs, poisons and poisoning in the focus of active substances, and is a scientific resource that scientists with basic science education will need to specialize in the field of forensic toxicology. We would like to thank the authors of all chapters with the hope that this content, which has been specially prepared for the 100th anniversary of The Republic of Türkiye, will be beneficial to all students and researchers who are trained to serve in the field of forensic sciences and contribute to the manifestation of justice and carry our country to a better tomorrow.

Assoc. Prof. Dr. Selda MERCAN
Assoc. Prof. Dr. Zeynep TÜRKMEN