The hyperfine field H(Sn) at the tin sites in Ni2MnSn has been measured by means of the Mössbauer effect at 300 and 77°K. The results, which are independent of heat treatment, have been extrapolated to 0°K to give a saturation field of +/-93 +/-3 kOe, in good agreement with a previous nuclear-magnetic-resonance measurement by Shinohara. H(Sn) has been calculated using the virtual-bound-state model, for a range of parameters of the theory. With the electronic ξ factor taken as 0. 04 and the magnetic moment per Mn ion as 4.0+/-0.1μB, agreement with experiment is obtained if the d-level occupation at Ni sites is 8. 6.