Despite the legislation and continuous improvement of agricultural practices, pesticide may hazardously move from the plots to the water resources and generate concentrations higher than the maximum levels fixed by the 80/788/EEC directive for drinking water. Then, grassed buffer strips may represent possible management tools to avoid or reduce the transfer from the application site to the main water bodies.Initially developed in the United-States to limit erosion and diffuse pollution by nutrients, the use of these systems has been extended from the 1990s to the reduction of diffuse contamination by pesticide. The monitoring of natural grassed strips has shown their potential to reduce pesticide transfer in runoff. Experiments led in controlled conditions have permitted to better understand the involved mechanisms. The wide existing results on these systems however still need to be supplemented. Processes have been characterized qualitatively but their respective contribution in a particular context is still misunderstood. Finally, we are unable to justify from a mechanistic point of view the effectiveness variability found experimentally. As a consequence, guidelines for implementation and management are mainly qualitative or result from an empirical approach. Furthermore, some results show that subsurface fluxes could exist under grassed strips and reduce their global efficiency.Thus, there is a need for a mechanistic approach of the grassed strip effectiveness. Numerical models should be useful to develop site-specific and dynamic tools which permit to test various implementation or management scenarios. Besides, specific studies on pesticide fate into the soil should allow a quantification of subsurface transfers and an identification of the situations of concern