The family of ABO3 perovskites forms an important class of materials with scientific value in several technological applications. Understanding the thermal properties of these materials helps determine different high-temperature applications such as thermal barrier coatings and thermoelectric devices. In this work, the thermal properties of the perovskites BaHfO3, BaSnO3, BaZrO3 and KTaO3 are studied using first-principles calculations. Each crystal was confirmed to be stable by phonon dispersion, and then the lattice contribution to thermal conductivity was calculated for each. BaZrO3 was found to have the lowest thermal conductivity of 5.291 Wm−1K−1 at 300 K and decreases to 1.092 W m−1K−1at 1500 K. BaHfO3 was found to have a thermal conductivity of 8.422 W m−1K−1 at 300 K and decreases to 1.728W m−1K−1 at 1500 K. BaSnO3 was found to have a thermal conductivity of 6.433 Wm−1K−1 at 300 K and decreases to 1.334 W m−1K−1 at 1500 K. KTaO3 was found to have a thermal conductivity of 17.793 W m−1K−1 at 300 K and decreases to 3.649W m−1K−1 at 1500 K. These results are quite comparable to experimental results at low temperature, however, are seriously underestimated at high temperatures