The ideal drain electrode assumed in the analysis of MOSFETs accepts carriers from the channel without reflection. The realistic drain, however, backscatters some of the carriers into the channel once again, and the backscattering is intensified if elastic scattering is dominant within the drain. The backscattering strongly affects the ballistic performance of MOSFETs. The channel length dependence of the ballistic performance of MOSFETs is explored in consideration of the backscattering. It is concluded that the ballistic limit of MOSFETs is not realized in the short-channel limit of the device, but, on the contrary, in the comparatively long-channel device in which minimization of the elastic scattering is pursued. The tendency may possibly explain the observed result that the performance of a 0.1 µm MOSFET reported a quarter-century ago showed a good agreement with the ballistic MOSFET characteristics.