Anchovy (Engraulis encrasicolus) is an important commercial species and one of the most abundant pelagic fish in the Gulf of Lions and the Catalan Sea. The factors influencing its recruitment are crucial to fisheries and ecological research. Among those factors transport of larvae by hydrodynamics (currents) is important because it determines whether the organisms can reach areas favourable to recruitment or are dispersed. Therefore, the first step in anchovy recruitment modelling is to simulate North-western Mediterranean Sea circulation. Several years (2001-2008) of hydrodynamics were simulated with the MARS-3D code. The resulting simulated currents and salinity are used by Lagrangian tool, Ichthyop, to transport anchovy eggs and larvae to the Western Mediterranean Sea. The aim of this study is to understand the main hydrodynamic processes that control anchovy transport and the effects of diel vertical migration on the transport and final distribution of anchovy.