The book of Alexander Pavlovich Efremov, candidate of biological sciences, provides data on the most important poisonous plants and mushrooms in the middle zone of the European part of Russia. The initial chapters are devoted to general pre-medical measures to provide first aid in case of poisoning, in a situation where it is not known from which type of plant or mushroom a person suffered. In the second part, a detailed description of poisonous plants and fungi is given, including their folk names, botanical description, color image, distribution and habitats, toxic parts and organs of the plant, poisonous principles and their effects, clinical picture and treatment. Such a book should not only be in every family, it should be a table at every district doctor, biology teacher, educator in summer children's camps, employees of camp sites, rest houses and sanatoriums, rural doctors and nurses, forestry workers, hunters, fishermen and, of course, mushroom pickers.