Bilge keels are effective devices to reduce rolling of ships. Normally, they can reduce rolling amplitude by about 20 to 50%. The initial cost of the bilge keel is minor, and the construction is simple. Many theoretical as well as experimental results regarding configuration, performance, and construction methods of bilge keels have been published. This Note is intended to present some experimental results of flanged bilge keels with and without slots in the end plate. It was found that flanged bilge keels without slots in the end plate yield less reduction of roll than those which are unflanged. However, the performance of flanged bilge keels can be improved by cutting slots in the end plate.