The influence of variable fluid properties on mixed electroosmotic and pressure driven flow of non-Newtonian fluids is investigated in this paper. The non-linear coupled energy and momentum equations are solved by means of an iterative numerical approach. The results reveal that the temperature dependent effects only become significant at very high values of the Debye-Hiickel parameter in case of combined electroosmotic and pressure driven flow and could safely be neglected in other cases. It is observed that the physical properties variation lead to a higher mean velocity in case of pressure assisted flow and a lower mean velocity in case of pressure opposed flow. Furthermore, the temperature dependent effects result in reduction of viscosity and the electrical resistivity over the majority of the channel cross section. It is also found that the shear-thinning fluids are more sensitive to fluid properties variation with temperature compared with Newtonian and shear-thickening fluids. (C) 2012 Elsevier B.V. All rights reserved.