[en] The Moessbauer effect probability is measured in single crystal tin samples oriented in the (100) and (001) planes under hydrostatic pressure up to 40 x 108 Pa. It is found that the anisotropy of the probability f001/f100 changes from 0.65 ± 0.02 at P = 0 to 0.90 ± 0.02 at P = 40 x 108 Pa. The experimental data for single crystals and polycrystals of tin under pressure are theoretically explained using the Brovman-Kagan model of lattice dynamics. (author)