A fuel injector for internal combustion engines is provided, which has a valve seat member, bordering a valve chamber, having a valve seat and spray orifices and a central blind-end bore as well as a valve member that is able to be driven to cause a lift motion having a closing head, which, together with a valve seat, forms a sealing seat lying upstream of the spray orifices. In order to prevent an underpressure developing in the blind-end bore in the closing phase of the sealing seat, and a partial return flow of the fuel connected with it, the closing head of the valve member is provided, at its end face facing towards the valve seat member, with a plunger sticking out from closing head, which has a shape adjusted to the contour of the blind-end bore, and dips into the blind-end bore when the sealing seat is closed.