The effect of pressure has been measured on the electrical resistance of fourteen oxides and five sulfides of transition metal ions, as well as on four ferrites. In general, the resistance decreased with increasing pressure at a faster rate for compounds with a high oxygen‐to‐metal ratio than for those with a lower ratio. For the semiconducting compounds the temperature coefficient of resistivity decreased with increasing pressure, but at a rate which would give metallic conduction only at very high pressures (0.7–2.0 Mbars). V2O5 and CrO3 exhibited phase transitions, but remained semiconducting in the high‐pressure phase. The sulfides showed markedly larger pressure coefficient of resistance than did the oxides.