Recognition of people from their biometric traits is entering relentlessly in the society by the push of the applications in security, privacy or natural man-machine interaction. Because of the different nature of the biometric traits and the peculiarities of the information acquisition, preprocessing, feature extraction and pattern matching of “biometric signatures”, the study of these technologies has to be addressed with a multidisciplinary vision. In this course we explain the technics of uni- and multi-dimensional signal processing and the technics of pattern recognition that are behind the current biometric systems. Also, less fundamental and more practical aspects of these systems are discussed from a point of view of his real applicability. The main pedagogical aim consists in that the student acquire the skill to use his knowledges on signal processing in an application in which exist external conditionings that impose important operation restrictions and that he/she is able to value the pros and cons of algorithmic decisions that are taken in the design of these systems.