Several very low probability light water reactor (LWR) accidents can potentially generate sufficient pressure to challenge the reactor containment integrity. A properly designed filtered vented containment system (FVCS) will prevent containment failure from overpressure and at the same time release only some low-risk fission product gases, which do not contaminate the ground. The existing and proposed FVCSs and other filter systems that could perform the same function are reviewed. Dry filters (fibrous mats, gravel beds, and sand beds), wet scrubbers (water pools, submerged gravel beds, washed fibrous mats, and submerged venturi), and combinations of different types of these filters have been proposed or used as FVCSs. The combination of two different filter types in series is particularly effective if they have substantially different aerosol penetration versus size characteristics. When cost/benefit analyses are considered, it is unclear in many cases whether FVCSs are cost-effective or actually reduce overall risk. At present, the U.S. Nuclear Regulatory Commission does not require FVCSs on commercial plants that it licenses. However, some U.S. Department of Energy reactor facilities are equipped with FVCSs and several U.S. utilities have proposed the installation of FVCSs at boiling water reactors (BWRs). They have not been required in Japan, Korea, India, Brazil, Taiwan, Argentina, or Switzerland. In contrast, many European countries believe that cost/benefit analyses have large uncertainties and cannot be used with confidence. They have opted for FVCSs to avoid the possibility of land contamination, to reduce the planned evacuation radius, and to provide an additional option for severe accident management. Although the first European FVCS installation was a large, expensive gravel-bed filter shared by two Swedish BWRs, the trend is toward the installation of small, lower cost FVCSs: sand beds or stainless steel fiber filters at French and German pressurized water reactors and multistage filters, consisting of a submerged venturi scrubber followed by a demister/filter, at German BWRs and Swedish LWRs.