The textbook is based on modern organic chemistry and considers the structure and chemical transformations of organic compounds, especially those that have biological importance. Special attention is given to the chemical reactions that have analogies in living systems. The book contains about 250 tasks on all topics and solutions for them. This book conforms to the Federal Educational Program on Bioorganic Chemistry for medical schools and universities. It is meant for students who study Bioorganic Chemistry during one term. The book may also be useful for teachers and students of specialized sec ondary schools with instruction conducted in English and colleges, whose main interest is medicine, pharmacy, biology and agriculture.