As part of a long-term project aimed at examining the rheology of fluorinated compounds of industrial importance, we have in an initial study been examining the ability of different potential models to predict the viscosity of perfluoroalkanes. Here we present a comparison of the viscosity of perfluorobutane predicted by molecular dynamics simulations using two different potential models with two experimentally based correlations, one of which is used in the DIPPR database, We find that the simulation data enables us to discriminate between two sets of published correlations for the viscosity of perfluorobutane.