Abstract: A process for preparing perfluoropolyoxyalkylenes having —OCF2H, —OCF2CF2H and —OCF(CF3)H end groups and a number average molecular weight from 120 to 3,000, by decarboxylation of the corresponding perfluoropolyoxyalkylenes having —OCF2COOH, —OCF2CF2COOH, —OCF(CF3)COOH end groups, in the presence of catalytic amounts of salts formed by perfluoropolyoxyalkylenes having end groups selected from —OCF2COOZ, —OCF2CF2COOZ and —OCF(CF3)COOZ, wherein Z is a monovalent cation of the group Ia or Ib or Z is —NR4+ wherein R is hydrogen or a C1-C4 alkyl, using ratios between Z and the —COOH equivalents of the perfluoropolyoxyalkylenes to be decarboxylated from 0.01 to 0.08, at a temperature between 120° C. and 180° C., in the presence of water, at pH <5 and at a pressure comprised between 2 and 80 atmospheres.