A fuel filter system, especially for Diesel engines includes filter housing (1) having a fuel inlet (27) and a fuel outlet (29) and a dehydrating filter medium (23) between the inlet and the outlet for the fuel to pass through. The filter housing (1) has a collection chamber (35) for the water trapped by the filter medium from which collection chamber the water can be supplied to a water absorbing and evaporating device (49) via a controlled dispenser (45). The components of the evaporating steam are releasable into the environment through the evaporating steam outlet (51). The water absorbing and evaporating device (49) has a valve arrangement (59, 61) by which the evaporating water outlet (51) can be closed depending on an inadmissible amount of non-evaporated water (55) collected in the evaporating device (49).