In this paper, we take into account the meaning Spanish intensivo prefixes provide for derived items, the restrictions that operate in this derivative process as well as the morphological characterization of these elements in Spanish prefix system. We consider prefixes such as ARCHI-, HIPER-, INFRA-, MACRO-, MEGA-, MICRO-, RE-, SEMI-, SOBRE-, SUB-, SUPER-, SUPRA-, and ULTRA-. As far as the meaning of complex words is concerned, intensive prefixes convoy a connotative sense, that can indicate a positive intensity or a negative one. In the first case, the intensification involves two degrees: superlative and augmentative. In the other case, it implies a diminishing sense. In relation to morphological characterization, intensive prefixes are c...