Direct perfluoroalkylation of aliphatic thiols was performed in the presence of sodium hydroxymethanesulfinate (Rongalite). Reaction of mercaptoalkanoic esters with trifluoromethyl bromide gave the corresponding trifluoromethylthio ethers. Condensation of alkane dithiols with perfluoroalkyl iodides led mainly to fluorinated dithioethers. These alkylation reactions are interpreted as occurring via in situ formation of dialkyldisulfides.