The problem of low- frequency lateral train-car vibration is an important issue surrounding the design of high-speed trains. Passive solutions such as stiffening the car chassis are impractical because of the weight increase. Semi-passive solutions, such as modifying the structural dynamics of the carboy through non-rigid coupling of heavy underfloor equipment does not come with a weight penalty, but do not sufficiently reduce the vibrations. However, computer simulations based on signals derived from a dynamic computer model of a train car indicates that the incorporation of a feedforward active control system, is likely to introduce a substantial reduction in the lateral vibration level. A simple controller structure is used and it is based on the multiple- input/single-output filtered-x LMS algorithm. Active control results illustrate an attenuation of the lateral train-car vibration by up to 14 dB.