A new representation of the viscosity of propane includes a zero-density correlation and an initial-density dependence correlation based on the kinetic theory of dilute gases and on the Rainwater–Friend theory. The higher density contributions of the residual viscosity in the representation are formed by a combination of double polynomials in density and reciprocal temperature, and a free-volume term with a temperature-dependent close-packed density. The full surface correlation is based on a set of primary experimental data selected as a result of a critical assessment of the available information from 37 original viscosity studies. The review refers to 96 citations altogether. The validity of the representation extends from the triple point to 600 K and 100 MPa in accordance with the modified Benedict–Webb–Rubin equation of state. The uncertainty of the representation varies from±0.4&percent;for the viscosity of the dilute gas phase between room temperature and 600 K, to about±2.5&percent;for the range 100–475 K up to about 30 MPa, and to about±4&percent;for points outside this range. Tables of the viscosity according to the representative equations at selected temperatures and pressures and along the saturation line provide easy reference as well as the validation of computer codes. ©1998 American Institute of Physics and American Chemical Society.