Ethology has been traditionally defined as ithe biological study of behaviori. Although its initial studies go back to the second half of the XIX century, its acknowledgement as a scientific discipline dates only from 1973, when the Nobel Prize for Medicine and Physiology is awarded to three of its most outstanding representatives: Konrad Lorenz, Niko Tinbergen and Karl von Frisch. In this text a journey that includes the main historical landmarks of ethology will be undertaken, making special emphasis on conceptual and theoretical aspects. A revision of the background that allows the establishment of ethology as a discipline will be made, as well as a view of its development