Because of the similarity in energy dependence of the 103Rh(n,n′) differential cross section to the kerma muscle response function for neutrons, rhodium may be useful as a neutron kerma monitor. In support of its use as a neutron monitor, the spectrum-averaged cross section has been measured for a 252Cf fission neutron spectrum. Pairs of thin rhodium samples were irradiated on opposite sides of a thinly encapsulated 252Cf neutron source. The neutron emission rate of the 252Cf source was determined by the manganous sulfate (MnSO4) bath technique. In this method, the californium source emission rate is determined by comparison to the known emission rate of NBS-I, a standard radium-beryllium neutron source. The neutron fluence incident on the rhodium samples is determined from the californium source strength, average sample-to-source distance, and the duration of the irradiation. Corrections are made for neutron scattering, saturation of activity, and attenuation of the X rays by the sample during counting. The X rays were detected with an intrinsic germanium detector designed specifically for low-energy X-ray detection. The activity was not determined by absolute counting so that the final results depend on the value of PKx, the total K X-ray emission probability. The results of five separate irradiations yield a value of . PKx = 62.3 ± 1.9 mb. Using the most recently published value of PKx gives a value of = 739 ± 22 mb. A discussion of systematic uncertainties is given.