In the recent years, a lot of progress has been done in diagnostic imaging techniques and their indications have been considerably diversified. Equine medicine has taken advantages of research and improvements made in the human field. Therefore, several imaging procedures can be used by the equine vet; indications and limitations of them are the essential criteria of choice for investigating a specific problem of the equine patient. The purpose of this paper is to demonstrate the criteria used in order to reach an exact diagnosis with the lower cost.