The textbook conforms to the requirements for training enhancement through the use of innovative technologies, competence-based learning in particular. The factors systematizing the content are issues of electronic structure of the carbon atom and organogens, chemical bonds, mutual influence of atoms within a molecule, conjugation and aromaticity, mechanisms of the most important types of reactions, and stereochemical repres entations. Much attention is paid to application of physicochemical methods of analysis. The authors have extended the section on the role of stereochemical structure in the manifestation of pharmacological activities of organic compounds. The authors present a set of newly introduced rules of the international systematic chemical nomenclature, which is especially important in the pharmaceutical industry, where medicinal products are mostly in the form of organic compounds. The textbook is written at a high scientific and methodological level, containing extensive re ference material, well-structured and supported by original illustrative material. The textbook is intended to students, specializing in Pharmacy. It may also be useful for students trained in the fields of chemistry, medical biochemistry, medical biophysics, and biotechnologies.