Bi-Maxwellian based 16-moment transport theory has been used extensively during the last 10 years to describe plasma flows in the terrestrial ionosphere and plasmasphere and in the solar wind. Here it is applied to the field-aligned flow of an electron-proton plasma between Saturn's ionosphere and inner magnetosphere. Assuming steady state conditions, numerical solutions to the model have been obtained for a wide variety of flow conditions corresponding to both subsonic outflow and subsonic inflow of plasma. In particular, the effect of varying the electron and proton temperature gradients at the ionospheric boundary has been studied, assuming a wide range of boundary densities and temperatures. The resulting electron and proton thermal structures at high altitudes exhibit both similarities and differences when compared to 16-moment theoretical predictions for the terrestrial ionosphere. ¿ American Geophysical Union 1995