Toxic effects of various plants are known to human beings since long time. Many plants are still in use to produce abortion or cattle poison in rural community. Sometimes plants are utilized for suicidal or homicidal purposes. Many times accidental poisoning may occur. In this book, we discussed general characteristics, active principles, mechanism of action, fatal dose, fatal period, signs and symptoms, treatment, postmortem findings and medico-legal importance of various important organic irritant poisons of plant origin as per Indian scenario. Details given in this book are very useful for undergraduate and postgraduate students of medicine and for the faculties dealing with autopsy.