The laminar flame burning velocities of 1,3,5-trimethylbenzene/air mixtures have been measured at atmospheric pressure and 400 K in a nearly constant pressure spherical bomb. A kinetic model has been constructed and tested against these new data and the extinction limits. The model performs well against the experimental flame speed data, whereas slightly overestimates the extinction limits. A pathway analysis shows that the fuel in both configurations reacts mainly through H abstraction reactions to produce a dimethylbenzyl radical. This radical then undergoes either an oxidation reaction with O atoms to produce aldehydes (dimethylbenzaldehyde and formaldehyde), or adds an H atom to form the initial fuel molecule. The branching ratio between these two reactions is strongly dependent either on the strain rate or the equivalence ration in diffusion and premixed flames, respectively.