The anisotropic emission of DD-fusion neutrons emitted by the plasma focus device PF-1000 at the Institute of Plasma Physics and Laser Microfusion, Warsaw, was observed with the use of thermoluminescent dosimeters and fast-neutron moderators. The observed anisotropy is compared with the computational prediction of the anisotropy caused by the PF-1000 vessel, which scatters the expanding DD-neutrons. The resulting changes in the group energy spectrum of neutrons induced by their scattering on the discharge vessel are presented and their effect on time-of-flight spectra of neutrons is discussed.