A new method for improving riding comfort by reducing vertical flexural vibrations in railway car bodies using piezoelectric elements is studied in this paper. Piezoelectric elements are attached on the car body in order to convert vibration energy to electrical energy, which can be dissipated in a shunt circuit. Assuming the car body as an elastically supported Bernoulli-Euler beam, theoretical analysis and numerical simulations are carried out. The numerical results are supplemented by experiments on a 1:5 scale model of a Shinkansen vehicle. Both numerical and experimental results indicate that the method yields significant vibration suppression with only a small amount of added weight. Two types of shunt circuits; a single-mode circuit and a multi-mode circuit are studied.