Crystallites isolated from an ingot of coarse-grained polycrystalline ZnTe, prepared by chemical vapour synthesis at a temperature of 650C, were studied by using X-ray diffractometry, luminescence, and the heat pulse technique. The crystallites were stacked in {110}-oriented macroscopic layers with a common twin system. The {111} twin planes separated at a distance of 50 to 100μm were perpendicular to the (110) growth layers. Acoustic phonon propagation was studied using the heat pulse technique. A comparison of the responses to the arrival of differently polarized phonons in a given sample with the responses obtained on high-purity coarse-grained ZnTe with randomly distributed twin systems with a separation of 5 to 10μm and on twin-free single-crystal ZnTe suggested that twins radically affect the scattering of acoustic phonons. The mean free paths of LA, FTA and STA phonons were determined by comparing the experimental responses with Monte Carlo calculations. Non-Equilibrium Acoustic Phonons in ZnTe at Liquid-Helium Temperatures - Effect of Impurities and Structural Defects on the Phonon Mean Free Path. V.S.Bagaev, T.I.Galkina, A.Y.Klokov, Y.V.Klevkov, V.S.Krivobok, V.P.Martovitskii, N.N.Sentyurina, A.I.Sharkov: Physics of the Solid State, 2005, 47[6], 1066-72