In many flame simulations, simplified transport models are used to reduce computational costs. This article presents the effect of simplified transport modeling on the burning velocity of laminar premixed flames. Results obtained with the detailed transport model are compared with results obtained with a number of simplified models. Furthermore, the influence of the Soret and Dufour effects is evaluated. All the models are tested on one-dimensional adiabatic premixed flames with CH4/air, CH4/O-2, H-2/air, and H-2/O-2 mixtures. Results show that the approximations may lead to large errors in the prediction of the burning velocity. For example, neglecting thermal diffusion in an H-2/air flame may lead to an error of 10%. Furthermore, simplified mass diffusion models appear to be inaccurate, especially for the fuel/oxygen flames.