Hanging-wall traps are successful trapping styles with discoveries made in many sedimentary basins worldwide. Examples of hanging-wall traps are documented in the literature but very few describe the role played by fault-rock seal on trap integrity. This contribution focuses on hanging-wall traps that are dependent on fault-rock seal. Analysis of 18 examples of hanging-wall traps has revealed that the hydrocarbon column height trapped by fault-rock seal is typically less than 190 m. Cross-plots of shale gouge ratio (SGR) and buoyancy pressure from hanging-wall traps have a similar data distribution to published SGR–buoyancy pressure calibration plots. The similarity in data distribution indicates a similarity in the overall fault-sealing mechanism: namely, the capillary fault sealing through the incorporation of clay/shale material into the fault zone. Published ‘global’ calibration plots of SGR v. buoyancy pressure can be used to evaluate the sealing or non-sealing risk of hanging-wall traps in the same manner as for footwall traps.