The electrical resistivity of TiB2 has been measured using a DIA-6 cubic anvil apparatus at pressures up to 8 GPa and temperatures up to 800 K. The ambient-condition resistivity is determined to be 13.3 (±0.9) μΩ cm. The resistivity decreases with increasing pressure. At pressures above 2 GPa, the pressure dependence of the resistivity is about −0.36 μΩ cm/GPa. On heating, the resistivity increases linearly with temperature. The measurements at simultaneously high pressure (3.2 GPa) and high temperatures yield a temperature dependence of 46 (±5) nΩ cm/K for the resistivity.