The normal-mode frequencies of lutetium were measured at 295 K by inelastic neutron scattering along the three main symmetry directions of the hexagonal lattice. The data are analyzed with a Born--von Karman force model including interactions up to the eighth-nearest neighbors. The phonon-frequency-distribution function is calculated, and from that the lattice specific heat and the Debye temperature. The latter are found to be in good agreement with results from other experimental techniques.