Purpose <p>The present paper aimed at studying effect of initial stress and micropolar couple modulus on the propagation of elastic waves in micropolar thermoelastic materials with voids.</p> Methods <p>We construct strain energy density function to develop the effect of initial stress on the basic equations of homogeneous-isotropic micropolar thermoelastic materials with voids. Seeking solutions for the basic equations, we obtain the effect of initial stress and micropolar couple modulus on the velocity and attenuation. Using the appropriate boundary conditions, we investigate the effect of initial stress and micropolar couple modulus on the reflection of the elastic waves for incident coupled longitudinal and shear waves.</p> Results <p>We obtain the reflection coefficients are function of initial stress and micropolar couple modulus and the other parameters. Numerically the effect of initial stress, micropolar couple modulus and the other parameters are observed, and the results are illustrated graphically for a particular model.</p> Conclusions <p>This study is theoretical investigation, and we do not provide any experimental evidence.</p>