A review of the history of mammalogy in Ecuador is presented. The chapter begins with the first documents published between the sixteenth and eighteenth centuries, in what has been called the Anecdotal Period, a time when the binomial nomenclature system and the classification proposed by Carl Linnaeus were not yet in use. The starting point of scientific knowledge of mammals in Ecuador is considered to be 1790, with the arrival of the Malaspina Expedition in the city of Guayaquil, during which some specimens were collected, and the first descriptions of the mammalian species of the country were made following Linnaeus’ guidelines. This historical chapter continues in the nineteenth century, with documentation of the most important expeditions for scientific purposes that took place in present-day Ecuador and their participants, including Alexander von Humboldt, Charles Darwin, Gaetano Osculati, Marcos Jiménez de la Espada, and others. The contribution made by different scientists between the end of the nineteenth century and the first half of the twentieth century is also analyzed. Finally, the chapter describes the events that, starting in the 1960s, changed the scientific history of the country, with the consequent appearance of the first Ecuadorian mammalogists and their contributions.