We have measured the thermal conductivity &kgr; of a single crystal of barium fluoride from room temperature down to 20 K. This material is used as a substrate for growth of PbTe and other semiconductor materials with applications as electronic devices. The room temperature value of &kgr; is 0.07 W cm−1 K−1, and the thermal conductivity increases as temperature is lowered. At 20 K, the onset of a peak is observed, with a maximum value of approximately 13 W cm−1K−1. The results are compared with existing data in the literature, and a fit to the data assuming Umklapp scattering of phonons is performed.