Inelastic neutron scattering has been performed on CHD3 molecules matrix isolated in solid argon. Four inelastic lines have been observed within the energy transfer range 0 less than or equal to (h) over bar omega 2.5 meV. The corresponding energy level scheme and the line intensities are explained in terms of a model based on a completely free rotation of the CHD3 molecule. An expression for the double differential neutron scattering cross section of the free CHD3 rotor is derived. In spite of a line shift of 44% with respect to the free rotor, no crystal field splitting was observed.