Abstract An explicit expression for the d-electron-lattice interaction in the layered compound TiCl3 is derived on the basis of the electronic band structure calculated by the tight-binding approximation. The frequency renormalization due to the d-electron-lattice interaction is calculated for all phonon modes of arbitrary wave vector. It is found that the renormalization of the Eg mode of Ti3+ ions at the center of the Brillouin zone is the largest. Then, taking into consideration the recent calculation of the phonon dispersion of ScCl3, it is concluded that the lattice distortion corresponding to the Eg mode of Ti3+ ions is most likely to be realized.