Radical (co)polymerization process of fluorinated olefinic monomers, optionally in association with one or more non-fluorinated olefins, in which the monomers are (co)polymerized in aqueous emulsion, in the presence of a hydrogenated chain transfer agent selected from hydrogen, aliphatic hydrocarbons and fluorohydrocarbons C.sub.1 -C.sub.20 and of a branched chain aliphatic alcohol C.sub.3 -C.sub.12 characterized by a ratio between the number of hydroxyl groups and the number of methyl groups lower than or equal to 0.5.