In the teaching-learning process of Mathematics in Elementary Education, one of the main difficulties is related to the development of geometric skills in schoolchildren. For this reason, the book focuses the study on geometric skills: recognizing geometric objects; tracing and/or constructing; arguing geometric propositions; and solving geometric calculation problems. The book provides the theoretical foundations for the development of geometric skills in elementary education: principles, actions, operations, levels and indicators. It also includes methodological recommendations for the treatment of the fundamental geometric objects that are addressed at this educational level, separated by cycle, due to the way in which the contents are treated in each of the grades. Teachers are also provided with the procedure to carry out some teaching aids for the treatment of geometric contents and the development of skills.