A fuel injection system for injecting fuel into the air intake tube of an internal combustion engine, including at least one fuel injection valve, which is disposed in a holder body and communicates with a fuel supply line and a fuel outflow line. The fuel injection valve is provided with a fuel supply groove, branching off from which are fuel inlet openings, and a fuel outflow groove, leading away from which are fuel outlet openings. The fuel injection valve is guided in the radial direction in a guide opening of the holder body by supporting bodies of a fuel filter which extends axially over the fuel injection valve, covering the fuel supply groove and the fuel outflow groove. The middle supporting body of the fuel filter is embodied such that it seals off the fuel supply line and the fuel supply groove from the fuel outflow line and the fuel outflow groove. In order to carry away vapor bubbles, there is either a degassing conduit embodied on the fuel injection valve between the fuel supply groove and the fuel outflow groove, a degassing conduit embodied on the middle supporting point, or a degassing conduit embodied on the holder body.