The interest in the supercritical fluid impregnation of polymeric materials stems from the opportunity to utilize high diffusivity, low surface tension and the ease of solvent recovery for the preparation of new polymeric materials. This term includes a wide range of applications of the supercritical impregnation process that will be discussed in this review: preparation of drug delivery systems via impregnation of an active principle in a polymer matrix, dye and organic metallic complexes impregnation and polymer blends preparation via impregnation of a monomer and an initiator in a swollen polymer matrix.