The present paper is concerned with wave propagation in a micropolar thermoelastic solid with temperature dependent properties under the effect of a gravitational field. The formulation of the problem was applied in the context of the threephase- lag model and Green–Naghdi theory without dissipation. The medium is a homogeneous isotropic thermoelastic in the half-space. The exact expressions of the considered variables were obtained using normal mode analysis. The results from the two theories were compared in the absence and presence of the gravitational field as well as temperature dependent properties. A comparison was also made for the two theories without micropolar constants.