AbstractThe lattice thermal conductivity of gadolinium monosulphide is studied by estimating the separate contributions due to transverse and longitudinal phonons in the temperature range 300 to 800 K and a very good agreement is found between calculated and experimental values. It is also reported that the transverse phonons are mainly responsible for the heat conduction in the present sample. The temperature exponents for the three phonon scattering relaxation rates is also reported for gadolinium monosulphide for the first time.