A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising: fluoropolyether acid or salt thereof having a number average molecular weight of at least about 800 g/mol; and fluorosurfactant having the formula: [R.sup.1--O.sup.n-L-A.sup.-] Y.sup.+ wherein: R.sup.1 is a linear or branched partially or fully fluorinated aliphatic group which may contain ether linkages; n is 0 or 1; L is a linear or branched alkylene group which may be nonfluorinated, partially fluorinated or fully fluorinated and which may contain ether linkages; A.sup.- is an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion, and phosphonate; and Y.sup.+ is hydrogen, ammonium or alkali metal cation; with the proviso that the chain length of R.sup.1--O.sub.n-L- is not greater than 6 atoms.