Simultaneous observations of the Gulf Stream surface and subsurface (15 ¿C at 200 m) fronts have shown their relative positions to be quite variable. Cross-frontal Ekman advection of the surface front by the local wind stress is a possible major source of this variability. We investigate this possibility and show that on the average and for a particular set of osbsevations, only a small fraction of the observed variability in the Gulf Stream surface-subsurface frontal separation is due to advection of the surface front by the local wind stress. As an alternative, it is suggested that most of the observed variability in frontal separation may be due to unstable meandering of the Gulf Stream surface front. ¿ American Geophysical Union 1988