The book "Medical Statistics - Basic Principles" includes the basic theory of medical statistics and develops the subject of medical statistical methodology in a simple, clear, and understandable way. In the 14 chapters of the book, the basic knowledge of statistical methodology is included, which concerns observations, experimental interventions in laboratory animals, patients, or healthy individuals. The examples used in most cases are numerous, allowing the reader to understand the reasoning that takes place before attempting to solve them. At the end of each chapter, exercises and their answers are provided. The book is aimed at doctors, dentists, biologists, pharmacists, and veterinarians, facilitating them in the application of appropriate tests and the processing of data from their research activities.