Abstract: The present invention relates to chemically stable, polyfunctional, perfluorinated polyorganosiloxanes (POS) comprising on the one hand fluorinated lateral grafts resulting from the hydrosilylation of perfluorinated olefins with SiH units and having alkyl and/or alkyl ester linkages but not ether linkages, and on the other hand other, non-perfluorinated functional units E capable of giving them diverse and varied physical and chemical properties and opening up avenues in numerous applications. Examples of these POS according to the invention are those of the following formula: According to another of its features, the invention relates to a process for the preparation of these polyfunctional perfluorinated POS. Applications: antifoams, agents for lowering surface tension, dirt repellents, antiadhesives, lubricants, oleophobic and/or hydrophobic agents, coatings etc.