The possibility that neutrons are generated by natural lightning was tested by mounting neutron dosimeters on lightning rods atop a 300-m tower 16 km west of Champaign, Illinois, for a period of 219 days. Upper limits on the neutron generation from 156 individual strokes within 6 cm of the dosimeters gave <3¿109 thermal neutrons per stroke and <2.5¿1010 of 2.45-MeV neutrons. These values are too low to have detectable physical or chemical effects on geochronological systems that could potentially have allowed erosion rates or lightning history to be measured. The observed fluxes of fast neutrons are, however, consistent with the cosmic ray background.