A process for the preparation of 1,1,1,3,3,3-hexafluoropropane is disclosed. The process involves (a) contacting at least one halopropane of the formula CF.sub.3CH.sub.2CH.sub.yX.sub.3-y (where each X is independently F, Cl or Br, and y is 3, 2, or 1) with Cl?2#191 in the presence of light or a free radical initiator to produce a mixture comprising CF.sub.3CH.sub.2CCI.sub.yX.sub.3-y; (b) contacting the CF.sub.3CH.sub.2CCI.sub.yX.sub.3-y produced in step (a) with HF, optionally in the presence of a fluorination catalyst, to produce a product mixture comprising CF.sub.3CH.sub.2CF.sub.3; and (c) recovering CF.sub.3CH.sub.2CF.sub.3 from the mixture produced in step (b).