This book was written to serve as a guide for undergraduate and postgraduate students and agricultural science professionals involved in the statistical analysis of experimental data, using practical examples from the field of animal nutrition. Due to the scarcity of material in Portuguese on the Rcommander (Rcmdr) package of the R programme, this book provides a general introduction to how to use the programme, thinking mainly of professionals and students who have never used this tool before. However, the material will also be useful for experienced R users, especially those who are not yet aware of the advantages of using a user-friendly graphical interface such as that provided by the Rcmdr package.