The subthreshold fission cross section of 240Pu was measured in the energy range from 10 to 250 keV, using 235U as a standard. Neutrons were produced via the 7Li(p,n) and T(p,n) reaction with the Karlsruhe 3-MV pulsed Van de Graaff accelerator. Fission events were registered by detecting fission neutrons with an NE-213 liquid scintillator with pulse-shape discriminator equipment. The high neutron flux available at flight paths of ∼67 and 135 mm allowed for a statistical accuracy of 1 to 3% together with a moderate energy resolution of ∼10 to 20 ns/m. The overall accuracy achieved is between 7 and 9%. The data show a distinct structure in the cross section, as indicated by poor statistics in previous measurements.