Viscosities are reported for two fluorinated propane isomers in the saturated-liquid state at temperatures from 262 K to 353 K. The compounds are 1,1,1,2,3,3-hexafluoropropane (R236ea) and 1,1,1,3,3,3-hexafluoropropane (R236fa). The measurements were performed in a capillary viscometer designed for fluids with vapor pressures above ambient. The estimated uncertainty of the viscosity measurements is +/-3%. A free-volume model was used to correlate the experimental results, and they were also compared with predictions from an extended corresponding states model.