Femtosecond laser surface texturing of materials by means of direct laser ablation has received a wide range of applications, not only in surface wettability control, but also for virus and bacterial repulsion. The wettability of laser-textured surfaces, however, experiences changes with time due to chemical surface modifications such as oxidation and/or molecular adsorption [1-2]. Despite their importance, these processes are not yet sufficiently studied. To better understand these effects, we propose a multiscale model, in which droplet behavior on laser-textured metal surfaces is calculated by using computational fluid dynamics (CFD) [3], while chemical surface modifications are simulated by using reactive molecular dynamics (MD). In particular, surface oxidation and molecular adsorption at the interface of Ti/TiO 2 by femtosecond laser ablation are simulated. The obtained reaction rates are then employed to change several interface parameters used in the CFD model. The simulation results show how the amount of oxygen (and carbon) attached to the surface modifies water droplet evolution. In particular, the calculated contact angle changes are found to agree with several previous experimental results. The obtained simulations are promising for explaining the time-dependent wetting transition effects that were experimentally observed for laser-textured materials.