A filter device, in particular for fluids polluted with admixtures of water, such as diesel oil, includes a filter housing (1) having a fluid inlet (43), a fluid outlet (44) and a filter element (9). During the filtering process, the fluid can flow through the filter medium (11) of the filter element from the unfiltered side (14) to the filtered side (13) of the filter medium and into its inner filter cavity (17). On at least one side of the filter medium (11), a water-separating system (23) has a separating region (25) for separated water. The water separating system is connected via at least one water opening (35) that is open toward the separating region (25) to a water collecting chamber (45). The filter element (9) has a passage (29) forming a fluid connection to the inner filter cavity (17) and can be connected to an element receptacle (47) of the filter housing (1). A fluid-conveying system (41) forms fluid paths separated from each other. The first fluid path (59/69) leads from the fluid inlet (43) of the housing (1) to the unfiltered side (14) of the filter element (9). The second fluid path (57) connects the respective water opening (35) to the water collecting chamber (45).